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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

for the quarterly period ended June 30, 2013

OR

for the transition period from                      to                     

Commission File Number: 001-34026

WHITING USA TRUST I

(Exact name of registrant as specified in its charter)

                                 1-800-852-1422                                 

(Registrant’s telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  ¨    No  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

As of August 9, 2013, 13,863,889 Units of Beneficial Interest in Whiting USA Trust I were outstanding.

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GLOSSARY OF CERTAIN DEFINITIONS

The following are definitions of significant terms used in this report:

“August 2013 distribution” The cash distribution to Trust unitholders of record on August 19, 2013 which is payable on or before August 29, 2013.

“Bbl” One stock tank barrel, or 42 U.S. gallons liquid volume, used in this report in reference to oil and other liquid hydrocarbons.

“BOE” One stock tank barrel of oil equivalent, computed on an approximate energy equivalent basis that one Bbl of crude oil equals six Mcf of natural gas and one Bbl of crude oil equals one Bbl of natural gas liquids.

“Btu or British thermal unit” The quantity of heat required to raise the temperature of one pound of water one degree Fahrenheit.

“completion” The installation of permanent equipment for the production of oil or natural gas, or in the case of a dry hole, the reporting of abandonment to the appropriate agency.

“COPAS” The Council of Petroleum Accountants Societies, Inc.

“costless collar” An options position where the proceeds from the sale of a call option at its inception fund the purchase of a put option at its inception.

“FASB ASC” The Financial Accounting Standards Board Accounting Standards Codification.

“February 2012 distribution” The cash distribution to Trust unitholders of record on February 17, 2012 that was paid on February 29, 2012.

“February 2013 distribution” The cash distribution to Trust unitholders of record on February 19, 2013 that was paid on March 1, 2013.

“field” An area consisting of either a single reservoir or multiple reservoirs, all grouped on or related to the same individual geological structural feature and/or stratigraphic condition. There may be two or more reservoirs in a field that are separated vertically by intervening impervious strata, or laterally by local geologic barriers, or both. Reservoirs that are associated by being in overlapping or adjacent fields may be treated as a single or common operational field. The geological terms “structural feature” and “stratigraphic condition” are intended to identify localized geological features as opposed to the broader terms of basins, trends, provinces, plays, areas of interest, etc.

“GAAP” Generally accepted accounting principles in the United States of America.

“gross wells” The total wells in which a working interest is owned.

“lease operating expense” or “LOE” The expenses of lifting oil or gas from a producing formation to the surface, constituting part of the current operating expenses of a working interest, and also including labor, superintendence, supplies, repairs, short-lived assets, maintenance, allocated overhead costs and other expenses incidental to production, but not including lease acquisition or drilling or completion expenses.

“May 2012 distribution” The cash distribution to Trust unitholders of record on May 20, 2012 (which resulted in an actual effective record date of May 18, 2012 due to May 20^th falling on a non-trading day) that was paid on May 30, 2012.

“May 2013 distribution” The cash distribution to Trust unitholders of record on May 20, 2013 that was paid on May 30, 2013.

“MBbl” One thousand barrels of crude oil or other liquid hydrocarbons.

“MBOE” One thousand BOE.

“Mcf” One thousand standard cubic feet of natural gas.

“MMBOE” One million BOE.

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“MMBtu” One million Btu.

“MMcf” One million standard cubic feet of natural gas.

“net profits interest” or “NPI” A nonoperating interest that creates a share in gross production from an operating or working interest in oil and natural gas properties. The share is measured by net profits from the sale of production after deducting costs associated with that production.

“net wells” The sum of the fractional working interests owned in gross wells, as the case may be.

“NYMEX” The New York Mercantile Exchange.

“plugging and abandonment” Refers to the sealing off of fluids in the strata penetrated by a well so that the fluids from one stratum will not escape into another or to the surface. Regulations of many states require plugging of abandoned wells.

“recompletion” An operation whereby a completion in one zone is abandoned in order to attempt a completion in a different zone within the existing wellbore.

“reserves” Estimated remaining quantities of oil and gas and related substances anticipated to be economically producible, as of a given date, by application of development projects to known accumulations. In addition, there must exist, or there must be a reasonable expectation that there will exist, the legal right to produce or a revenue interest in the production, installed means of delivering oil and gas or related substances to market, and all permits and financing required to implement the project.

“reservoir” A porous and permeable underground formation containing a natural accumulation of producible crude oil and/or natural gas that is confined by impermeable rock or water barriers and is individual and separate from other reservoirs.

“SEC” The United States Securities and Exchange Commission.

“working interest” The interest in a crude oil and natural gas property (normally a leasehold interest) that gives the owner the right to drill, produce and conduct operations on the property and to share in production, subject to all royalties, overriding royalties and other burdens and to share in all costs of exploration, development and operations and all risks in connection therewith.

“workover” Operations on a producing well to restore or increase production.

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PART I – FINANCIAL INFORMATION

Item 1. Financial Statements

WHITING USA TRUST I

Statements of Assets, Liabilities and Trust Corpus (Unaudited)

(In thousands, except unit data)

Statements of Distributable Income (Unaudited)

(In thousands, except distributable income per unit data)

The accompanying notes are an integral part of these modified cash basis financial statements.

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WHITING USA TRUST I

NOTES TO MODIFIED CASH BASIS FINANCIAL STATEMENTS

(Unaudited)

1. ORGANIZATION OF THE TRUST

Formation of the Trust — Whiting USA Trust I (the “Trust”) is a statutory trust formed in October 2007 under the Delaware Statutory Trust Act, pursuant to a trust agreement (the “Trust agreement”) among Whiting Oil and Gas Corporation and Equity Oil Company, as trustors, The Bank of New York Trust Company, N.A., as trustee (subsequently renamed The Bank of New York Mellon Trust Company, N.A., and hereinafter referred to as the “Trustee”) and Wilmington Trust Company as Delaware trustee (the “Delaware Trustee”). The initial capitalization of the Trust estate was funded by Whiting Petroleum Corporation (“Whiting”) in November 2007. Effective September 30, 2009, Equity Oil Company merged into Whiting Oil and Gas Corporation (“Whiting Oil and Gas”) with Whiting Oil and Gas as the surviving corporation. Whiting Oil and Gas, as referred to herein, is a subsidiary of Whiting and the successor to Equity Oil Company.

The Trust was created to acquire and hold a term NPI for the benefit of the Trust unitholders pursuant to a conveyance to the Trust from Whiting Oil and Gas. The term NPI is an interest in certain of Whiting Oil and Gas’ properties located in the Rocky Mountains, Mid-Continent, Permian Basin and Gulf Coast regions (the “underlying properties”). The NPI is the only asset of the Trust, other than cash reserves held for Trust expenses. As of December 31, 2012, these oil and gas properties included interests in 3,081 gross (368.0 net) producing oil and gas wells.

The NPI is passive in nature, and the Trustee has no management control over and no responsibility relating to the operation of the underlying properties. The NPI entitles the Trust to receive 90% of the net proceeds from the sale of production from the underlying properties. The NPI will terminate when 9.11 MMBOE have been produced and sold from the underlying properties (which amount is the equivalent of 8.20 MMBOE in respect of the Trust’s right to receive 90% of the net proceeds from such reserves pursuant to the NPI), and the Trust will soon thereafter wind up its affairs and terminate, after which it will pay no further distributions. As of June 30, 2013 on a cumulative accrual basis, 6.61 MMBOE (81%) of the Trust’s total 8.20 MMBOE have been produced and sold and a cumulative reserve quantity of 0.02 MMBOE have been sold in divestitures. The remaining reserve quantities are projected to be produced by June 30, 2015, based on the reserve report for the underlying properties as of December 31, 2012. The Trust’s Annual Report on Form 10-K includes additional information on the Trust’s reserves as of December 31, 2012.

The Trustee can authorize the Trust to borrow money to pay Trust administrative or incidental expenses that exceed cash held by the Trust. The Trustee may authorize the Trust to borrow from the Trustee, Whiting, or the Delaware Trustee as a lender provided that the terms of the loan are similar to the terms it would grant to a similarly situated commercial customer with whom it did not have a fiduciary relationship. The Trustee may also deposit funds awaiting distribution in an account with itself, which may be a non-interest bearing account, and make other short-term investments with the funds distributable to the Trust.

Initial Issuance of Trust Units and Net Profits Interest Conveyance — In April 2008, the Trust issued 13,863,889 Trust units to Whiting in exchange for the conveyance of the term NPI, which is described above, from Whiting Oil and Gas. Immediately thereafter, Whiting completed an initial public offering of units of beneficial interest in the Trust, selling 11,677,500 Trust units to the public. Whiting retained, and has continued to retain, an ownership in 2,186,389 Trust units, or 15.8% of the total Trust units issued and outstanding.

2. BASIS OF ACCOUNTING

Interim Financial Statements — The accompanying unaudited financial information has been prepared by the Trustee in accordance with the instructions to the Quarterly Report on Form 10-Q. The accompanying financial information is prepared on a comprehensive basis of accounting other than GAAP. The Trustee believes that the information furnished reflects all adjustments (consisting of normal and recurring adjustments) which are, in the opinion of the Trustee, necessary for a fair presentation of the results for the interim periods presented. Operating results for the periods presented are not necessarily indicative of the results that may be expected for the full year. The Trust’s 2012 Annual Report on Form 10-K includes certain definitions and a summary of significant accounting policies and should be read in conjunction with this Quarterly Report on Form 10-Q.

Term Net Profits Interest — The Trust uses the modified cash basis of accounting to report Trust receipts from the term NPI and payments of expenses incurred. The actual cash distributions to the Trust are made based on the terms of the conveyance that created the Trust’s NPI. The term NPI entitles the Trust to receive revenues (oil, gas and natural gas liquid sales) less expenses (the amount by which all royalties, lease operating expenses including well workover costs, production and property taxes, payments made by

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Whiting to the hedge counterparty upon settlements of hedge contracts, maintenance expenses, post-production costs including plugging and abandonment, and producing overhead, exceed hedge payments received by Whiting under hedge contracts and other non-production revenue) of the underlying properties multiplied by 90% (term NPI percentage). Actual cash receipts may vary due to timing delays of cash receipts from the property operators or purchasers and due to wellhead and pipeline volume balancing agreements or practices.

Modified Cash Basis of Accounting — The financial statements of the Trust, as prepared on a modified cash basis, reflect the Trust’s assets, liabilities, Trust corpus, earnings and distributions as follows:

While these statements differ from financial statements prepared in accordance with GAAP, the modified cash basis of reporting revenues and distributions is considered to be the most meaningful for the Trust’s activities and results because quarterly distributions to the Trust unitholders are based on net cash receipts. This comprehensive basis of accounting other than GAAP corresponds to the accounting permitted for royalty trusts by the SEC as specified by FASB ASC Topic 932, Extractive Activities – Oil and Gas: Financial Statements of Royalty Trusts.

Most accounting pronouncements apply to entities whose financial statements are prepared in accordance with GAAP, directing such entities to accrue or defer revenues and expenses in a period other than when such revenues are received or expenses are paid. Because the Trust’s financial statements are prepared on the modified cash basis as described above, however, most accounting pronouncements are not applicable to the Trust’s financial statements.

Recent Accounting Pronouncements — There were no accounting pronouncements issued during the six months ended June 30, 2013 applicable to the Trust or its financial statements.

3. INVESTMENT IN NET PROFITS INTEREST

Whiting Oil and Gas conveyed the NPI to the Trust in exchange for 13,863,889 Trust units. The investment in net profits interest was recorded at the historical cost basis of Whiting on April 30, 2008, the date of conveyance, and was determined to be $123.6 million, of which $111.2 million (90% of the NPI) was attributed to the Trust. As of June 30, 2013 and December 31, 2012, accumulated amortization of the investment in net profits interest was $86.7 million and $80.2 million, respectively.

4. INCOME TAXES

The Trust is a grantor trust and therefore is not subject to federal income taxes. Accordingly, no recognition has been given to federal income taxes in the Trust’s financial statements. The Trust unitholders are treated as the owners of Trust income and corpus, and the entire taxable income of the Trust is reported by the Trust unitholders on their respective tax returns.

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For Montana state income tax purposes, Whiting must withhold from its NPI payments to the Trust, an amount equal to 6% of the net amount payable to the Trust from the sale of oil and gas in Montana. For Alabama, Arkansas, Colorado, Kansas, Louisiana, Michigan, Mississippi, New Mexico, North Dakota, Oklahoma and Utah, neither the Trust nor Whiting is withholding the income tax due such states on distributions made to an individual resident or nonresident Trust unitholder, as long as the Trust is taxed as a grantor trust under the Internal Revenue Code.

5. DISTRIBUTION TO UNITHOLDERS

Actual cash distributions to the Trust unitholders depend on the volumes of and prices received for oil, natural gas and natural gas liquids produced from the underlying properties, among other factors. Quarterly cash distributions during the term of the Trust are made by the Trustee no later than 60 days following the end of each quarter (or the next succeeding business day) to the Trust unitholders of record on the 50th day following the end of each quarter. Such amounts equal the excess, if any, of the cash received by the Trust during the quarter, over the expenses of the Trust paid during such quarter, subject to any adjustments for changes made by the Trustee during such quarter in any cash reserves established for future expenses of the Trust.

6. RELATED PARTY TRANSACTIONS

Capital Expenditures — During the three and six months ended June 30, 2013, Whiting incurred $1.2 million and $2.3 million, respectively, of capital expenditures on the underlying properties. These capital expenditures are the costs net to Whiting’s interest in the wells and which are related to the drilling and completing of oil and gas wells, capital workovers, facility upgrades and well recompletions that are performed to secure production from new horizons. Pursuant to the terms of the conveyance agreement, such expenditures were not deducted from gross proceeds or the Trust distributions, but they may have the effect of ultimately accelerating the receipt of NPI net proceeds and thereby benefiting the Trust unitholders by accelerating their return on investment. The Trust cannot provide any assurance that this will continue to occur or that future capital expenditures will be consistent with historical levels.

Operating Overhead — Pursuant to the terms of the applicable joint operating agreements, Whiting deducts from the gross proceeds an overhead fee to operate those underlying properties for which Whiting has been designated as the operator. Additionally, with respect to those underlying properties for which Whiting is the operator but where there is no operating agreement in place, Whiting deducts from the gross proceeds an overhead fee calculated in the same manner that Whiting allocates overhead to other similarly owned properties, which is customary practice in the oil and gas industry. Operating overhead activities include various engineering, legal and administrative functions. The fee is adjusted annually pursuant to COPAS guidelines and will increase or decrease each year based on changes in the year-end index of average weekly earnings of crude petroleum and natural gas workers. The following table presents the Trust’s portion of these overhead charges for the distributions made during the three and six months ended June 30, 2013 and 2012:

Administrative Services Fee — Under the terms of the administrative services agreement, the Trust pays a quarterly administration fee of $50,000 to Whiting 60 days following the end of each calendar quarter. General and administrative expenses in the Trust’s statements of distributable income for the three and six months ended June 30, 2013 include $50,000 and $100,000, respectively, for quarterly administrative fees paid to Whiting. General and administrative expenses in the Trust’s statements of distributable income for the three and six months ended June 30, 2012 include $50,000 and $100,000, respectively, for quarterly administrative fees paid to Whiting.

Trustee Administrative Fee — Under the terms of the Trust agreement, the Trust pays an annual administrative fee to the Trustee of $160,000, paid in four quarterly installments of $40,000 each and is billed in arrears. General and administrative expenses in the Trust’s statements of distributable income for the three and six months ended June 30, 2013 include $40,000 and $80,000, respectively, for quarterly administrative fees paid to the Trustee. General and administrative expenses in the Trust’s statements of distributable income for the three and six months ended June 30, 2012 include $40,000 and $80,000, respectively, for quarterly administrative fees paid to the Trustee.

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Letter of Credit — In February 2011, Whiting established a $1.0 million letter of credit for the Trustee in order to provide it with a mechanism to pay the operating expenses of the Trust, in the event that Whiting should fail to lend funds to the Trust if requested to do so by the Trustee. This letter of credit will not be used to fund NPI distributions to unitholders, and Whiting has no obligation to lend funds to the Trust. If the Trustee were to draw on the letter of credit or borrow funds from Whiting or otherwise, no further distributions would be made to unitholders until all such amounts have been repaid by the Trust.

7. SUBSEQUENT EVENT

On August 7, 2013, the Trustee announced the Trust distribution of net profits for the second quarterly payment period in 2013. Unitholders of record on August 19, 2013 are expected to receive a distribution of $0.533550 per Trust unit, which is payable on or before August 29, 2013. This aggregate distribution to all Trust unitholders is expected to consist of net cash proceeds of $7.7 million paid by Whiting to the Trust, less a provision of $225,000 for estimated Trust expenses and $46,185 for Montana state income tax withholdings.

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Item 2. Trustee’s Discussion and Analysis of Financial Condition and Results of Operations

References to the “Trust” in this document refer to Whiting USA Trust I. References to “Whiting” in this document refer to Whiting Petroleum Corporation and its wholly-owned subsidiaries. References to “Whiting Oil and Gas” in this document refer to Whiting Oil and Gas Corporation, a wholly-owned subsidiary of Whiting Petroleum Corporation and the successor to Equity Oil Company. Equity Oil Company was merged into Whiting Oil and Gas Corporation effective September 30, 2009. The merger did not have an effect on the Trust.

The following review of the Trust’s financial condition and results of operations should be read in conjunction with the financial statements and notes thereto, as well as the Trustee’s discussion and analysis contained in the Trust’s 2012 Annual Report on Form 10-K. The Trust’s Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and all amendments to those reports are available on the SEC’s website www.sec.gov.

Note Regarding Forward-Looking Statements

This Quarterly Report on Form 10-Q includes “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements other than statements of historical facts included in this Quarterly Report on Form 10-Q, including without limitation the statements under “Trustee’s Discussion and Analysis of Financial Condition and Results of Operations” are forward-looking statements. No assurance can be given that such expectations will prove to have been correct. When used in this document, the words “believes,” “expects,” “anticipates,” “projects,” “intends” or similar expressions are intended to identify such forward-looking statements. The following important factors, in addition to those discussed elsewhere in this Quarterly Report on Form 10-Q, could affect the future results of the energy industry in general, and Whiting and the Trust in particular, and could cause actual results to differ materially from those expressed in such forward-looking statements:

All subsequent written and oral forward-looking statements attributable to Whiting or the Trust or persons acting on behalf of Whiting or the Trust are expressly qualified in their entirety by these factors. The Trustee assumes no obligation, and disclaims any duty, to update these forward-looking statements.

Overview and Trust Termination

The Trust does not conduct any operations or activities. The Trust’s purpose is, in general, to hold the NPI, to distribute to unitholders cash that the Trust receives in respect of the NPI, and to perform certain administrative functions in respect of the NPI and the Trust units. The Trust derives substantially all of its income and cash flows from the NPI, which was in turn subject to commodity hedge contracts through December 31, 2012 (which hedging effects impacted the February 2013 distribution to unitholders and ceased thereafter). The NPI entitles the Trust to receive 90% of the net proceeds from the sale of production from the underlying properties.

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Oil and gas prices historically have been volatile and may fluctuate widely in the future. The table below highlights these price trends by listing quarterly average NYMEX crude oil and natural gas prices for the periods indicated through June 30, 2013. The May 2013 distribution in the second quarter of 2013 was mainly affected, however, by January 2013 through March 2013 oil prices and December 2012 through February 2013 natural gas prices.

Lower oil and gas prices on production from the underlying properties could cause the following: (i) a reduction in the amount of net proceeds to which the Trust is entitled; (ii) a reduction in the amount of oil, natural gas and natural gas liquids that is economic to produce from the underlying properties; and (iii) an extension of the length of time required to produce 9.11 MMBOE (8.20 MMBOE at the 90% NPI) due to some wells thereby reaching their economic limits sooner. Alternatively, higher oil and natural gas prices may potentially result in an increase in the amount of oil, natural gas and natural gas liquids that is economic to produce from the underlying properties. All costless collar hedge contracts Whiting entered into, and in turn conveyed to the Trust, terminated as of December 31, 2012 (which hedging effects impacted the February 2013 distribution to unitholders and ceased thereafter) and no additional hedges are allowed to be placed on the Trust assets. Consequently, for production applicable to quarterly payment periods after the February 2013 distribution, there will be no cash settlement gains or losses on commodity derivatives, and the Trust will have increased exposure to oil and natural gas price volatility.

Trust termination. The NPI will terminate when 9.11 MMBOE have been produced and sold from the underlying properties (which amount is equivalent to 8.20 MMBOE attributable to the NPI), and the Trust will soon thereafter wind up its affairs and terminate, after which it will pay no further distributions. Since the assets of the Trust are depleting assets, a portion of each cash distribution paid on the Trust units should be considered by investors as a return of capital, with the remainder being considered as a return on investment or yield. As a result, the market price of the Trust units will decline to zero at termination of the Trust. As of June 30, 2013 on a cumulative accrual basis, 6.61 MMBOE (81%) of the Trust’s total 8.20 MMBOE have been produced and sold (of which proceeds from the sale of 255 MBOE, which is 90% of 284 MBOE, will be distributed to unitholders in the Trust’s forthcoming August 2013 distribution) and a cumulative reserve quantity of 0.02 MMBOE have been divested. For additional discussion relating to, and of the assumptions underlying, the estimated date when 9.11 MMBOE (8.20 MMBOE at the 90% NPI) will be produced and sold from the underlying properties, after which the Trust will soon thereafter wind up its affairs and terminate, see “Description of the Underlying Properties” in Item 2 of the Trust’s 2012 Annual Report on Form 10-K.

Results of Trust Operations

Six Months Ended June 30, 2013 Compared to Six Months Ended June 30, 2012

The following is a summary of income from net profits interest received by the Trust for the six months ended June 30, 2013 and 2012, consisting of the February and May distributions for each respective year (dollars in thousands, except per Bbl, per Mcf and per BOE amounts):

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Income from Net Profits Interest. Income from net profits interest is recorded on a cash basis when NPI proceeds are received by the Trust from Whiting. NPI proceeds that Whiting remits to the Trust are based on the oil and gas production Whiting has received payment for within one month following the end of the most recent fiscal quarter. Whiting receives payment for its crude oil sales generally within 30 days following the month in which it is produced, and Whiting receives payment for its natural gas sales generally within 60 days following the month in which it is produced. Income from net profits interest is generally a function of oil and gas revenues, lease operating expenses, production taxes and cash settlements on commodity derivatives as follows:

Revenues. Oil and natural gas revenues decreased $4.5 million or 12% for the six months ended June 30, 2013 as compared to the same period in 2012. Revenues are a function of oil and natural gas sales prices and production volumes sold. The decrease in revenue between periods was due to lower sales prices realized for oil and natural gas and lower oil and natural gas production volumes during the first half of 2013 as compared to the first half of 2012. The average price for oil decreased 7% between periods, and the average price for gas before the effects of hedging decreased 10%. Oil sales volumes decreased 5% or 20 MBbls, and gas sales volumes decreased 8% or 105 MMcf during the first six months of 2013 compared to the same period in 2012. Both of these volume decreases were primarily related to normal field production decline but were also impacted between reporting periods by differences in timing associated with revenues distributed and received from non-operated properties. The oil volume decline was partially offset by oil production increases from three recently drilled oil wells that came online during the last twelve months. In the December 31, 2012 reserve report, natural gas production attributable to the underlying properties is estimated to decline at rates ranging from 11% to 13% annually from 2013 through the estimated June 30, 2015 NPI termination date, while oil production is estimated to decline at approximately 9% annually over this same time period.

Lease Operating Expenses. Lease operating expenses (“LOE”) increased $0.4 million or 3% during the first six months of 2013 compared to the first six months of 2012, primarily due to an increase of $0.2 million in higher labor costs on Whiting-operated properties and a $0.2 million increase in the cost of oilfield goods and services between periods. The increase in overall LOE

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coupled with the decrease in overall production volumes between periods resulted in an increase in LOE on a per BOE basis of 9%, from $23.63 during the first half of 2012 to $25.85 for the same period in 2013. LOE per BOE may be subject to increases in the future as overall production rates decline at a faster rate than fixed and semi-variable costs attributable to the underlying properties.

Production Taxes. Production taxes are typically calculated as a percentage of oil and natural gas revenues before the effects of hedging, and production taxes as a percent of revenues remained consistent at 7.1% for the first half of 2013 and 2012. Overall production taxes for the six months ended June 30, 2013 decreased, however, by $0.3 million or 12% compared to the same period in 2012, primarily due to lower oil and gas sales revenue between periods.

Cash Settlements on Commodity Derivatives. In connection with Whiting’s conveyance of the net profits interest to the Trust, Whiting entered into certain costless collar hedge contracts in order to reduce the Trust’s exposure to commodity price volatility. If market prices were lower than a collar’s price floor when the cash settlement amount was calculated, Whiting received cash proceeds from the contract counterparty. Conversely, if market prices were higher than a collar’s price ceiling when the cash settlement amount was calculated, Whiting was required to pay the contract counterparty.

Cash settlements relating to these hedges resulted in a gain of $1.4 million for the six months ended June 30, 2013, which had the effect of increasing the average price of natural gas by $1.08 per Mcf for that period, and cash settlements relating to these hedges also resulted in a gain of $3.2 million for the six months ended June 30, 2012, which had the effect of increasing the average price of natural gas by $2.31 per Mcf for that period. As a result, the total net price of natural gas of $4.37 per Mcf and $5.97 per Mcf that the Trust received for the six months ended June 30, 2013 and 2012, respectively, included premiums of 25% and 39%, respectively, related to the effects of hedging for those same periods. However, all hedge related pricing impacts ceased after the February 2013 distribution, which is included in the results of trust operations for the six months ended June 30, 2013 presented above, while the Trust’s oil and gas reserves are currently projected to terminate in June 2015 based on the Trust’s December 31, 2012 reserve report. Therefore, no commodity price hedges were in effect during the quarterly payment period covered by the May 2013 distribution, nor will there be hedges in effect during any future Trust distributions through Trust termination, which has the effect of increasing the Trust’s exposure to oil and natural gas price volatility.

General and Administrative Expenses. For the six months ended June 30, 2013 and 2012, the Trust’s general and administrative expenses remained consistent at $0.5 million for each respective period.

Distributable Income. For the six months ended June 30, 2013, the Trust’s distributable income was $14.3 million and was based on income from net profits interest of $14.8 million, reduced by Trust general and administrative costs of $0.5 million and Montana state income tax withholdings of $0.1 million, and adjusted for changes in Trust cash reserves. This compares to distributable income of $20.0 million for the first six months of 2012, which was based on income from net profits interest of $20.5 million, reduced by $0.5 million of Trust administrative expenses and $0.2 million in Montana state income tax withholdings, and adjusted for changes in Trust cash reserves.

Three Months Ended June 30, 2013 Compared to Three Months Ended June 30, 2012

The following is a summary of income from net profits interest received by the Trust for the three months ended June 30, 2013 and 2012, consisting of the May distribution for each respective year (dollars in thousands, except per Bbl, per Mcf and per BOE amounts):

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Income from Net Profits Interest. Income from net profits interest is recorded on a cash basis when NPI proceeds are received by the Trust from Whiting. NPI proceeds that Whiting remits to the Trust are based on the oil and gas production Whiting has received payment for within one month following the end of the most recent fiscal quarter. Whiting receives payment for its crude oil sales generally within 30 days following the month in which it is produced, and Whiting receives payment for its natural gas sales generally within 60 days following the month in which it is produced. Income from net profits interest is generally a function of oil and gas revenues, lease operating expenses, production taxes and cash settlements on commodity derivatives as follows:

Revenues. Oil and natural gas revenues decreased $2.8 million or 15% for the three months ended June 30, 2013 as compared to the same period in 2012. Revenues are a function of oil and natural gas sales prices and production volumes sold. The decrease in revenue between periods was due to lower sales prices realized for oil and lower oil and natural gas production volumes, partially offset by a higher sales price realized for natural gas during the second quarter of 2013 as compared to the second quarter of 2012. The average price for oil decreased 7% between periods, while the average price for gas before the effects of hedging increased 6%. Oil sales volumes decreased 11% or 21 MBbls, and gas sales volumes decreased 3% or 23 MMcf during the second quarter of 2013 compared to the same period in 2012. Both of these volume decreases were primarily related to normal field production decline, and were also impacted between reporting periods by differences in timing associated with revenues distributed and received from non-operated properties. In the December 31, 2012 reserve report, natural gas production attributable to the underlying properties is estimated to decline at rates ranging from 11% to 13% annually from 2013 through the estimated June 30, 2015 NPI termination date, while oil production is estimated to decline at approximately 9% annually over this same time period.

Lease Operating Expenses. LOE decreased $0.3 million or 4% during the second quarter of 2013 compared to the second quarter of 2012, primarily due to a decrease of $0.4 million in plug and abandonment charges, partially offset by a $0.1 million increase

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in the cost of oilfield goods and services between periods. LOE on a per BOE basis, however, increased 5% from $24.96 during the second quarter of 2012 to $26.14 for the same period in 2013. This higher LOE rate was mainly due to overall production declining at a faster rate than the fixed and semi-variable costs attributable to the underlying properties.

Production Taxes. Production taxes are typically calculated as a percentage of oil and natural gas revenues before the effects of hedging, and production taxes as a percent of revenues remained relatively consistent at 7.0% and 7.1% for the second quarter of 2013 and 2012, respectively. Overall production taxes for the three months ended June 30, 2013 decreased, however, by $0.2 million or 16% compared to the same period in 2012, primarily due to lower oil sales revenue between periods.

Cash Settlements on Commodity Derivatives. In connection with Whiting’s conveyance of the net profits interest to the Trust, Whiting entered into certain costless collar hedge contracts in order to reduce the Trust’s exposure to commodity price volatility. If market prices were lower than a collar’s price floor when the cash settlement amount was calculated, Whiting received cash proceeds from the contract counterparty. Conversely, if market prices were higher than a collar’s price ceiling when the cash settlement amount was calculated, Whiting was required to pay the contract counterparty.

All hedges terminated as of December 31, 2012, and all hedge related pricing impacts ceased after the February 2013 distribution. Thus, there were no hedges in effect or related cash settlements during the second quarter of 2013. Cash settlements relating to these hedges resulted in a gain of $1.8 million for the second quarter of 2012, however, which had the effect of increasing the average price of natural gas by $2.67 per Mcf for that period. As a result, the total net price of natural gas of $5.98 per Mcf that the Trust received for the three months ended June 30, 2012 included a premium of 45% related to the effects of hedging for that period. Although the hedges terminated as of the February 2013 distribution, the Trust’s oil and gas reserves are currently projected to terminate in June 2015 based on the Trust’s December 31, 2012 reserve report. Therefore, no commodity price hedges will impact future Trust distributions through Trust termination, which has the effect of increasing the Trust’s exposure to oil and natural gas price volatility.

General and Administrative Expenses. For the three months ended June 30, 2013 and 2012, the Trust’s general and administrative expenses remained consistent at $0.3 million for each respective period.

Distributable Income. For the three months ended June 30, 2013, the Trust’s distributable income was $6.3 million and was based on income from net profits interest of $6.6 million, reduced by Trust general and administrative costs of $0.3 million and Montana state income tax withholdings of $0.05 million, and adjusted for changes in Trust cash reserves. This compares to distributable income of $10.0 million for the second quarter of 2012, which was based on income from net profits interest of $10.3 million, reduced by $0.3 million of Trust administrative expenses and $0.1 million in Montana state income tax withholdings, and adjusted for changes in Trust cash reserves.

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Liquidity and Capital Resources

The Trust has no source of liquidity or capital resources other than cash flows from the NPI. Other than Trust administrative expenses, including any reserves established by the Trustee for future liabilities, the Trust’s only use of cash is for distributions to Trust unitholders. Administrative expenses include payments to the Trustee and the Delaware Trustee, a quarterly fee to Whiting pursuant to an administrative services agreement, and expenses in connection with the discharge of the Trustee’s duties, including third party engineering, audit, accounting and legal fees. Each quarter, the Trustee determines the amount of funds available for distribution to unitholders. Available funds are the excess cash, if any, received by the Trust from the NPI and other sources (such as interest earned on any amounts reserved by the Trustee) that quarter, over the Trust’s expenses for that quarter. Available funds are reduced by any cash the Trustee decides to hold as a reserve against future liabilities. The Trustee may borrow funds required to pay liabilities if the Trustee determines that the cash on hand and the cash to be received are insufficient to cover the Trust’s liabilities. If the Trustee borrows funds, the Trust unitholders will not receive distributions until the borrowed funds are repaid.

Income to the Trust from the NPI is based on the calculation and definitions of “gross proceeds” and “net proceeds” contained in the conveyance agreement, which is listed as an exhibit to this report, and reference is hereby made to such conveyance agreement for the actual definitions of “gross proceeds” and “net proceeds”.

Although capital expenditures for the testing, drilling, completion, equipping, plugging back or recompletion of any well that is a part of the underlying properties cannot be deducted from gross proceeds pursuant to the terms of the conveyance agreement, Whiting incurred capital expenditures of $2.3 million on the underlying properties during the six months ended June 30, 2013. Such expenditures were not deducted from gross proceeds or Trust distributions, but they may have the effect of ultimately accelerating the receipt of NPI net proceeds and thereby benefiting the Trust unitholders by accelerating their return on investment. The Trust cannot provide any assurance that this will continue to occur or that future capital expenditures will be consistent with historical levels.

In February 2011, Whiting established a $1.0 million letter of credit for the Trustee in order to provide a mechanism for the Trustee to pay the operating expenses of the Trust, in the event that Whiting should fail to lend funds to the Trust if requested to do so by the Trustee. This letter of credit will not be used to fund NPI distributions to unitholders, and Whiting has no obligation to lend funds to the Trust. If the Trustee were to draw on the letter of credit or borrow funds from Whiting or otherwise, no further distributions would be made to unitholders until all such amounts have been repaid by the Trust.

The Trust does not have any transactions, arrangements or other relationships with unconsolidated entities or persons that could materially affect the Trust’s liquidity or the availability of capital resources.

Future Trust Distributions to Unitholders

On August 7, 2013, the Trustee announced the Trust distribution of net profits for the second quarterly payment period in 2013. Unitholders of record on August 19, 2013 are expected to receive a distribution of $0.533550 per Trust unit, which is payable on or before August 29, 2013. This aggregate distribution to all Trust unitholders is expected to consist of net cash proceeds of $7.7 million paid by Whiting to the Trust, less a provision of $225,000 for estimated Trust expenses and $46,185 for Montana state income tax withholdings.

New Accounting Pronouncements

There were no accounting pronouncements issued during the six months ended June 30, 2013 applicable to the Trust or its financial statements.

Critical Accounting Policies and Estimates

A disclosure of critical accounting policies and the more significant judgments and estimates used in the preparation of the Trust’s financial statements is included in Item 7 of the Trust’s Annual Report on Form 10-K for the year ended December 31, 2012. There have been no significant changes to the critical accounting policies during the six months ended June 30, 2013.

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Item 3. Quantitative and Qualitative Disclosures About Market Risk

Commodity Hedge Contracts

The primary asset of and source of income to the Trust is the term NPI, which generally entitles the Trust to receive 90% of the net proceeds from oil and gas production from the underlying properties. Consequently, the Trust is exposed to market risk from fluctuations in oil and gas prices. Through the February 2013 distribution, however, the NPI was subject to commodity hedge contracts in the form of costless collars entered into by Whiting, which reduced the NPI’s exposure to commodity price volatility. The revenues derived from the underlying properties depend substantially on prevailing crude oil, natural gas and natural gas liquid prices. As a result, commodity prices also affect the amount of cash flow available for distribution to the Trust unitholders. Lower prices may also reduce the amount of oil, natural gas and natural gas liquids that Whiting can economically produce. Whiting sells the oil, natural gas and natural gas liquid production from the underlying properties under floating market price contracts each month. Whiting entered into certain hedge contracts through December 31, 2012 (which had effects extending through the February 2013 distribution to unitholders) to manage the exposure to crude oil and natural gas price volatility, which is associated with revenues generated from the underlying properties, and to achieve more predictable cash flows. However, all hedging contracts terminated as of December 31, 2012, which effects in turn terminated as of the February 2013 distribution. No additional hedges are allowed to be placed on Trust assets, nor can the Trust enter into derivative contracts for speculative or trading purposes.

Crude oil costless collar arrangements settle based on the average of the closing settlement price for each commodity business day in the contract period. Natural gas costless collar arrangements settle based on the closing settlement price on the second to last scheduled trading day of the month prior to delivery. In a collar arrangement, the counterparty is required to make a payment to Whiting for the difference between the fixed floor price and the settlement price if the settlement price is below the fixed floor price. Whiting was required to make a payment to the hedge counterparty for the difference between the fixed ceiling price and the settlement price if the settlement price was above the fixed ceiling price. The amount received by Whiting from the counterparty upon settlements of the hedge contracts reduced the operating expenses related to the underlying properties when calculating net proceeds. Commodity derivative contracts that settled from October through December 2012 provided cash receipts of $1.2 million (90% of $1.4 million) which were included in the February 2013 distribution to Trust unitholders.

Item 4. Controls and Procedures

Evaluation of Disclosure Controls and Procedures. The Trustee maintains disclosure controls and procedures designed to ensure that information required to be disclosed by the Trust in the reports that it files or submits under the Securities Exchange Act of 1934, as amended, is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include controls and procedures designed to ensure that information required to be disclosed by the Trust is accumulated and communicated by Whiting to The Bank of New York Mellon Trust Company, N.A., as Trustee of the Trust, and its employees who participate in the preparation of the Trust’s periodic reports as appropriate to allow timely decisions regarding required disclosure.

As of the end of the period covered by this report, the Trustee carried out an evaluation of the Trustee’s disclosure controls and procedures. Mike Ulrich, as Trust Officer of the Trustee, has concluded that the disclosure controls and procedures of the Trust are effective.

Due to the contractual arrangements of (i) the Trust agreement and (ii) the conveyance of the NPI, the Trustee relies on (A) information provided by Whiting, including historical operating data, plans for future operating and capital expenditures, reserve information and information relating to projected production, and (B) conclusions and reports regarding reserves by the Trust’s independent reserve engineers. For a description of certain risks relating to these arrangements and risks relating to the Trustee’s reliance on information reported by Whiting and included in the Trust’s results of operations, see the Trust’s Annual Report on Form 10-K for the fiscal year ended December 31, 2012, Item 1A. Risk Factors “The Trust and the Trust unitholders have no voting or managerial rights with respect to the underlying properties. As a result, neither the Trust nor the unitholders have any ability to influence the operation of the underlying properties”.

Changes in Internal Control over Financial Reporting. During the quarter ended June 30, 2013, there has been no change in the Trustee’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Trustee’s internal control over financial reporting relating to the Trust. The Trustee notes for purposes of clarification that it has no authority over, and makes no statement concerning, the internal control over financial reporting of Whiting.

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PART II – OTHER INFORMATION

Item 1A. Risk Factors

Risk factors relating to the Trust are contained in Item 1A of the Trust’s Annual Report on Form 10-K for the fiscal year ended December 31, 2012. No material change to such risk factors has occurred during the six months ended June 30, 2013.

Item 6. Exhibits

The exhibits listed in the accompanying index to exhibits are filed as part of the Quarterly Report on Form 10-Q.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

Date: August 9, 2013

The Registrant, Whiting USA Trust I, has no principal executive officer, principal financial officer, board of directors or persons performing similar functions. Accordingly, no additional signatures are available, and none have been provided. In signing the report above, the Trustee does not imply that it has performed any such function or that such function exists pursuant to the terms of the Trust agreement under which it serves.

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EXHIBIT INDEX

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