Exhibit 99.1

FOR IMMEDIATE RELEASE:

Guaranty Bancorp Announces 2011 Third Quarter Financial Results

·                  Quarterly net income increases to $2.2 million, or 52.8% from the previous linked quarter

·                  Significant reduction in classified assets of $30.0 million, or 26.9% during the quarter

·                  Growth in pass-rated loans of $22.1 million, or 2.2% during the quarter

·                  Tangible Common Equity Ratio increases to 9.4% as compared to 5.0% at June 30, 2011 due to the early conversion of preferred stock during the quarter; Equity Ratio improves to 10.0%

·                  Growth in core deposits of $51.7 million, or 5.0% during the quarter

DENVER, October 20, 2011 — Guaranty Bancorp (Nasdaq: GBNK) today reported third quarter 2011 net income of $2.2 million compared to a net loss of $4.0 million in the third quarter 2010.  The earnings per common share calculation for the current quarter included a non-cash adjustment of approximately $16.8 million, or $0.32 per basic and diluted common share, related to the regular quarterly paid-in-kind dividend on the Company’s Series A Convertible Preferred Stock and the previously announced transaction that accelerated the conversion of the Series A Convertible Preferred Stock into common stock. With this adjustment to earnings per common share, the Company reported a loss of $0.28 per basic and diluted common share for the current quarter compared to a loss of $0.11 per basic and diluted common share for the same period a year ago. Without this adjustment, the Company would have reported positive earnings per common share. This adjustment was the final adjustment to the earnings per common share computation related to the Company’s Series A Convertible Preferred Stock.  As a result of this accelerated conversion of all shares of our preferred stock, the 9% dividend on such shares was eliminated and the Company’s consolidated capital ratios improved significantly.

Paul W. Taylor, Guaranty Bancorp’s President and Chief Executive Officer, stated, “I am pleased to announce our third consecutive quarter of improved earnings and credit quality. In addition to quarterly net income of $2.2 million, our key credit quality measure of classified assets to Tier 1 capital and allowance fell to 42.6% at the end of the third quarter as compared to 56.3% at the end of the previous quarter. Further, the early conversion of our preferred stock in the third quarter significantly improved several of our key capital ratios. Our leverage ratio increased to 11.4% at September 30, 2011 as compared to 6.7% at the end of the prior quarter.  Similarly, our tangible common equity ratio improved to 9.4% at the end of the third quarter as compared to 5.0% at June 30, 2011. In addition, our equity ratio improved to 10.0% as compared to 9.5% as June 30, 2011.  Our strong capital ratios are significant because they do not, and never did, include any government monies or funds.”

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Mr. Taylor continued, “While our total outstanding loans declined slightly this quarter, due mostly to expected payoffs and reductions in problem loans, we have continued our success in generating new loan business. We originated $84.8 million of new loans in the third quarter, our strongest quarter in over two years.  In addition, our core deposit balances increased $51.7 million during the quarter.”

For the nine months ended September 30, 2011, net income was $4.1 million compared to a net loss of $10.2 million for the same period in 2010. The earnings per common share calculation included a non-cash adjustment of approximately $19.8 million, or $0.38 per basic and diluted common share, related to three quarters of paid-in-kind preferred stock dividends and the previously announced mandatory accelerated conversion of the Company’s Series A Convertible Preferred Stock into common stock.  After giving effect to the preferred stock dividends and mandatory accelerated conversion of preferred stock, the loss per basic and diluted common share for the first nine months of 2011 was $0.30 per share compared to a loss per basic and diluted common share of $0.28 for the same period in 2010.  Net income improved due to a $10.9 million reduction in provision for loan losses, a $12.4 million reduction in noninterest expense primarily related to other real estate owned and a $2.0 million reduction in FDIC assessments.  These considerable income improvements were partially offset by a $4.4 million decrease in net interest income due mostly to a reduced level of earning assets in 2011 as well as a $6.3 million decrease in income tax benefit.

Key Financial Measures

Income Statement

Balance Sheet

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Net Interest Income and Margin

Third quarter 2011 net interest income of $15.1 million increased by $0.4 million compared to the second quarter 2011 and decreased by $1.1 million from the third quarter 2010.  The Company’s net interest margin of 3.62% for the third quarter 2011 reflected an increase of six basis points from the second quarter 2011 and an increase of nine basis points from the third quarter 2010.

Although net interest income increased by $0.4 million during the third quarter 2011 compared to the second quarter 2011, interest income decreased by $0.2 million mostly due to lower loan fee income. Offsetting this slight decline in interest income, interest expense declined by $0.5 million due to a $72.0 million decrease in average time deposits, mostly higher-cost, brokered time deposits. The Company anticipates further reductions in time deposit interest in the fourth quarter of 2011 as a result of scheduled maturities of brokered deposits of $29.2 million with a weighted average cost of 1.86%.

Net interest income decreased by $1.1 million in the third quarter 2011, as compared to the same quarter in 2010, primarily due to an unfavorable $1.9 million volume variance, partially offset by a $0.8 million favorable rate variance. The unfavorable volume variance for the third quarter 2011 as compared to the same quarter in 2010 is due mostly to the $247.9 million decrease in average loan balances, offset by an $83.5 million increase in the average balance of all other earning assets, and a $323.0 million decrease in average time deposits. The favorable rate variance for the third quarter 2011 as compared to the same quarter in 2010 is primarily due to a 74 basis point decrease in the cost of deposits, partially offset by a 35 basis point decrease in the yield on earning assets.  Despite the decrease in net interest income, overall net interest margin improved by nine basis points to 3.62% in the third quarter 2011 as compared to 3.53% in the same quarter in 2010.

Net interest income for the first nine months of 2011 decreased by $4.4 million from $49.0 million for the nine months ended September 2010 to $44.6 million for the nine months ended September 2011. The $4.4 million decline consists of a $5.3 million unfavorable volume variance, partially offset by a $0.9 million favorable rate variance.   The unfavorable volume variance for the first nine months of 2011 as compared to the same period in 2010 is due mostly to a $284.2 million decline in average loan balances, partially offset by a $99.7 million increase in the average balance of all other earning assets and a $296.6 million decrease in average time deposits.  The favorable rate variance for the first nine months of 2011 as compared to the same period in 2010 is due to the 55 basis point decrease in the cost of deposits, partially offset by the 33 basis point decrease in the yield on earning assets.

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Noninterest Income

The following table presents noninterest income as of the dates indicated:

The $3.2 million increase in noninterest income in the third quarter 2011 as compared to the second quarter 2011 reflects a $3.3 million change in gain/loss on sale of securities from the $0.3 million loss recognized in the second quarter to the $3.0 million gain recognized in the third quarter.  The decision to sell several mortgage-backed securities was primarily based on the expectation that these securities were expected to have significant increases in prepayment speeds, as well as an opportunity to retire $51 million of higher cost Federal Home Loan Bank (“FHLB”) term advances.  The Company determined that it would be advantageous to recognize the unrealized gain on these securities in order to pay the prepayment penalties on the FHLB advances, rather than holding the securities and being repaid at par value. Excluding the $3.0 million gain on securities recognized in the third quarter 2011, noninterest income remained relatively flat compared to the same quarter in 2010.

Excluding the $1.2 million gain on sale of loans recognized in June 2010, noninterest income for the nine months ended September 30, 2011 increased by $3.6 million compared to the same period in 2010.  This increase is primarily the result of a $3.3 million increase in net gains on sale of securities.  Additionally, customer service and other fees increased by $0.3 million year over year, primarily as a result of higher overdraft and interchange fee income.

Noninterest Expense

The following table presents noninterest expense as of the dates indicated:

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The $2.8 million increase in noninterest expense in the third quarter 2011 as compared to the second quarter 2011 is due mostly to a $2.7 million prepayment penalty on the early payoff of $51.0 million Federal Home Loan Bank term advances, an increase in other general and administrative expense of $0.3 million, and a $0.4 million decrease in expenses related to other real estate owned.  As noted above, this $2.7 million prepayment penalty was fully offset by the gain from the sale of mortgage-backed securities. The increase in other general and administrative expense is primarily due to an increase in collection-related expense. The decrease in other real estate owned expense is primarily due to an increase of $0.3 million in operating income from a single property.

Noninterest expense for the nine months ended September 30, 2011 decreased by $11.6 million compared to the same period in 2010 primarily due to a $12.4 million decrease in expenses associated with other real estate owned, a $2.0 million decrease in insurance and assessment expenses, and a $0.8 million decrease in amortization of intangible assets, partially offset by a $0.8 million aggregate increase in several other general and administrative categories and a $2.7 million increase in prepayment penalties related to long-term borrowings as explained above.  The decrease in other real estate owned expense for the year-to-date period in 2011 as compared to the same period in 2010 is mostly due to a reduction in net write-downs on other real estate owned properties resulting from valuation adjustments and sales. The decrease in insurance and assessment expense for the first nine months of 2011 as compared to the same period in 2010 is due primarily to a favorable change in our risk classification in the third quarter 2010 as well as the implementation of new rules mandated by the Dodd-Frank Wall Street Reform and Consumer Protection Act. These new rules changed the assessment base from total deposits to average total assets less tangible capital, but also significantly lowered the assessment rates, causing a net favorable impact on our FDIC insurance premiums.

Preferred Stock Dividend/Mandatory Early Conversion of Preferred Stock

Effective August 15, 2011, a regular, quarterly non-cash preferred stock dividend was paid in the form of additional shares of Series A Convertible Preferred Stock to holders of Series A Convertible Preferred Stock in the amount of $1.6 million.  For the nine months ended September 30, 2011, the regular, quarterly, paid-in-kind preferred stock dividend was $4.6 million.

Effective September 30, 2011, a special non-cash preferred stock dividend was paid in the form of additional shares of Series A Convertible Preferred Stock to holders of Series A Convertible Preferred Stock in the amount of $7.3 million pursuant to the Amended and Restated Series A Convertible Preferred Stock Transaction Agreement (the “Transaction Agreement”), dated August 9, 2011, approved by the Company’s stockholders at a special meeting held on September 29, 2011.

The Transaction Agreement also provided for an acceleration of its outstanding Series A Convertible Preferred Stock into the Company’s common stock.  After obtaining regulatory and stockholder approval, on September 30, 2011, the Company completed the accelerated conversion, including the payment of the above mentioned  special paid-in-kind preferred stock dividend, whereby all the outstanding shares of Series A Convertible Preferred Stock, with a liquidation value of $77.9 million (carrying value $76.6 million), were converted into approximately 51.9 million shares of the Company’s common stock, including approximately 12.7 million shares resulting from the combination of the special paid-in-kind dividend and adjustment to the conversion ratio

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pursuant to the Transaction Agreement. As a result of the special paid-in-kind preferred stock dividend and the adjustment to the conversion ratio, the Company incurred a one-time, non-cash adjustment of approximately $15.2 million in its calculation of basic and diluted earnings per common share during the quarter and nine months ended September 30, 2011.

Balance Sheet

At September 30, 2011, the Company had total assets of $1.7 billion, which represented a $177.7 million decline as compared to December 31, 2010 and a $240.8 million decline as compared to September 30, 2010.  The decline in assets from December 31, 2010 is primarily due to a $116.2 million decrease in loans, net of unearned discount. The loan decline was due mostly to a $113.3 million decrease in commercial loans, partially offset by a $4.1 million increase in real estate loans.

In the third quarter 2011, our classified loans declined by $23.6 million and loans internally classified as special mention or watch declined by $14.4 million.  In addition to this $38.0 million decline in classified and watch rated loans, other real estate owned decreased by $6.4 million in the third quarter 2011.  These declines were the result of the continued successful execution of our strategic plan to reduce problem assets.

Pass-rated loans consist of all loans not otherwise adversely classified.  A watch rated loan is still considered pass-rated, but is monitored monthly for potential downgrade. As described above, loans that are adversely classified or on our internal watch list decreased by $38.0 million in the third quarter. While total loans declined slightly by $2.8 million in the third quarter 2011, our pass-rated loans increased by $22.1 million during the third quarter.  In addition, our pipeline of new loan opportunities continued to grow each month.

As discussed above, the Company sold $86.4 million in mortgage-backed securities in September 2011. The decision was primarily based on the expectation that these securities were expected to have significant increases in prepayment speeds, as well as an opportunity to retire $51 million of higher cost FHLB term advances. Through October 11, 2011, the Company purchased $43.2 million in replacement mortgage-backed securities.

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The following table sets forth the amounts of our loans outstanding (excluding loans held for sale) at the dates indicated:

Since September 30, 2010, the ratio of construction, land and land development loans to capital fell by 19 percentage points to 67% at September 30, 2011.   Similarly, the ratio of commercial real estate loans to capital fell by 44 percentage points to 253% at September 30, 2011.  These ratios are below the regulatory commercial real estate concentration guidelines of 100% for land and construction loans and 300% for all investor real estate loans, respectively.

The following table sets forth the amounts of our deposits outstanding at the dates indicated:

Noninterest-bearing deposits as a percentage of total deposits increased to 33.3% at September 30, 2011, as compared to 25.6% at December 31, 2010 and 23.7% at September 30, 2010.

Non-maturing deposits at September 30, 2011 increased by $96.1 million as compared to December 31, 2010 and increased by $144.2 million compared to September 30, 2010.  In addition to the $96.1 million increase in balances of non-maturity deposits in 2011, the total number of customer accounts increased by over 2.3% during the same period.

Time deposits continue to decrease primarily as a result of management’s efforts to reduce the overall level of higher cost time deposits, particularly brokered and internet deposits. Total brokered deposits at September 30, 2011 were $39.7 million as compared to $179.9 million at December 31, 2010 and $206.0 million at September 30, 2010.  Brokered deposits represented 2.9% of total deposits at September 30, 2011 as compared to 12.2% at December 31, 2010 and 13.5% at September 30, 2010.  In addition to this $166.3 million decline in brokered deposits over the past twelve months, we also experienced a $75.7 million decline in internet time deposits over the same time period. The remaining decline in time deposits is primarily related to the non-renewal

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of other higher cost certificates of deposits.  Management monitors time deposit maturities and renewals on a daily basis and will raise rates on local time deposits if necessary to grow such deposits.

Borrowings were $110.2 million at September 30, 2011 as compared to $163.2 million at December 31, 2010 and $164.2 million at September 30, 2010.  The Company elected to payoff $51 million of Federal Home Loan Bank term advances in September 2011. The weighted average rate of these advances was 3.50% with maturity dates that ranged from November 2011 to February 2014. The entire balance of borrowings at each balance sheet date consists of term advances with the Federal Home Loan Bank.

Regulatory Capital Ratios

All of the Company’s and subsidiary bank’s regulatory capital ratios are above the highest regulatory capital threshold of “well-capitalized” at September 30, 2011.  The Company’s and the subsidiary bank’s actual capital ratios for September 30, 2011 and December 31, 2010 are presented in the table below:

The improvements in the consolidated Tier 1 risk-based capital ratio and leverage ratio are primarily attributable to the mandatory accelerated conversion of preferred stock.   In prior periods, the preferred stock was treated for Tier 1 capital purposes as a restricted core capital element limited to 25% of total Tier 1 capital.  After the conversion, the newly converted common stock is treated as an unrestricted core capital element, which significantly improves our Tier 1 and leverage ratios.

Generally, the allowance for loan losses is included in total capital for regulatory purposes; however, it is limited to 1.25% of total risk-weighted assets.  At September 30, 2011, approximately $19.6 million of the subsidiary bank’s allowance for loan losses was disallowed from being included in total risk-based capital under the regulatory capital rules, or approximately 1.51% of the consolidated risk-weighted assets.  In addition, approximately $1.3 million of deferred tax assets were disallowed for purposes of computing consolidated Tier 1 capital.

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Asset Quality

The following table presents select asset quality data (excluding loans held for sale) as of the dates indicated:

(1)Past due loans include both loans that are past due with respect to payments and loans that are past due because the loan has matured, and are in the process of renewal, but continue to be current with respect to payments.

The following table summarizes our past due loans by class (excluding loans held for sale) as of the dates indicated:

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During the third quarter 2011, all categories of classified and watch list loans declined by an aggregate of $37.9 million.  In particular, during the third quarter 2011, nonaccrual loans decreased by $10.6 million, other classified loans decreased by $13.0 million and loans classified as special mention or watch decreased by $14.4 million.  Nonaccrual loans decreased due to $4.0 million of net charge-offs, with the remainder due mostly to loan payoffs, net of new additions.

Net charge-offs in the third quarter 2011 were $4.0 million as compared to $9.0 million in the second quarter 2011 and $7.5 million in the third quarter 2010.  Approximately $3.1 million of the charge-offs in the third quarter were related to eight customers, with an outstanding balance of $3.5 million prior to the charge-offs.  Approximately half of these charge offs in the third quarter were specifically allocated as of June 30, 2011.

The general component of the allowance for loan losses decreased slightly from $34.7 million at June 30, 2011.  The majority of this decline is due to an adjustment in the historical component of the allowance, based on lower levels of charge offs replacing higher levels of charge offs from prior periods. The general component represented 2.88% of loans, net of unearned discount, at September 30, 2011 as compared to 3.18% of loans, net of unearned discount, at the end of the previous quarter.

The Company recorded a provision for loan losses in the third quarter 2011 of $1.0 million, as compared to $1.0 million in the second quarter 2011 and $2.5 million in the third quarter 2010.  The consistent level in the provision for loan losses quarter over quarter reflects the continued shrinkage of our loan portfolio combined with the fact that half of the charge-offs taken in the third quarter were specifically reserved for as of June 30, 2011.

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Shares Outstanding

As of September 30, 2011, the Company had 105,300,569 shares of common stock outstanding, consisting of 100,205,569 shares of voting common stock and 5,095,000 shares of non-voting common stock. The total common shares outstanding of 105,300,569 shares includes 1,668,959 shares of unvested stock awards, but excluding 156,567 shares of common stock to be issued under its deferred compensation plan.

Effective September 30, 2011, the Company consummated the accelerated conversion of its Series A Convertible Preferred Stock pursuant to the Transaction Agreement. The Company issued to the holders of Series A Convertible Preferred Stock an aggregate of 7,294 shares of Series A Convertible Preferred Stock as a special payment-in-kind dividend and, immediately thereafter, issued an aggregate of 49,416,505 shares of its voting common stock and 2,485,502 shares of its non-voting common stock to the holders of Series A Convertible Preferred Stock in connection with the accelerated mandatory conversion of the Series A Convertible Preferred Stock at a conversion price of $1.50 per share. All of the non-voting common stock was issued to Castle Creek Capital Partners IV, LP (“CC Fund IV”). Additionally, immediately following the consummation of the transaction, CC Fund IV, as permitted by the Company’s certificate of incorporation, elected, with the prior approval of the Company, to convert 2,609,498 shares of voting common stock held by it into an equal number of shares of non-voting common stock, resulting in CC Fund IV owning an aggregate of 5,095,000 shares of non-voting common stock.

Non-GAAP Financial Measures

This press release includes non-GAAP financial measures related to tangible assets, including tangible book value, tangible book value after giving effect to conversion of preferred stock, and tangible equity ratio, all of which exclude intangible assets.

The Company discloses these non-GAAP financial measures to provide meaningful supplemental information regarding the Company’s operational performance and to enhance investors’ overall understanding of the Company’s core financial performance. Management believes that these non-GAAP financial measures allow for additional transparency and are used by some investors, analysts and other users of the Company’s financial information as performance measures. These non-GAAP financial measures are presented for supplemental informational purposes only and should not be considered a substitute for financial information presented in accordance with GAAP. These non-GAAP financial measures presented by the Company may be different from non-GAAP financial measures used by other companies.

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The following non-GAAP schedules reconcile the book value per share to the tangible book value per share and the GAAP equity ratio to the tangible equity ratio as of the dates indicated:

Tangible Common Equity Ratio

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About Guaranty Bancorp

Guaranty Bancorp is a bank holding company that operates 34 branches in Colorado through a single bank, Guaranty Bank and Trust Company. The bank provides banking and other financial services including real estate, construction, commercial and industrial, energy, consumer and agricultural loans throughout its targeted Colorado markets to consumers and small to medium-sized businesses, including the owners and employees of those businesses. The bank also provides trust services, including personal trust administration, estate settlement, investment management accounts and self-directed IRAs. More information about Guaranty Bancorp can be found at www.gbnk.com.

Forward-Looking Statements

This press release contains forward-looking statements, which are included in accordance with the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. In some cases, you can identify forward-looking statements by terminology such as “may,” “will,” “should,” “could,” “expects,” “plans,” “intends,” “anticipates,” “believes,” “estimates,” “predicts,” “potential,” or “continue,” or the negative of such terms and other comparable terminology.  These forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause the Company’s actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements.  Such factors include, among others, the following: failure to maintain adequate levels of capital and liquidity to support Company’s operations; the effect of the regulatory written agreement the Company and its bank subsidiary have entered into and potential future supervisory action against the Company or its bank subsidiary; general economic and business conditions in those areas in which the Company operates; demographic changes; competition; fluctuations in interest rates; continued ability to attract and employ qualified personnel; ability to receive regulatory approval for our bank subsidiary to declare dividends to the Company; adequacy of our allowance for loan losses, changes in credit quality and the effect of credit quality on our provision for credit losses and allowance for loan losses; changes in governmental legislation or regulation, including, but not limited to, any increase in FDIC insurance premiums; changes in accounting policies and practices; changes in the deferred tax asset valuation allowance; changes in business strategy or development plans; changes in the securities markets; changes in consumer spending, borrowing and savings habits; the availability of capital from private or government sources; competition for loans and deposits and failure to attract or retain loans and deposits; changes in the financial performance and/or condition of our borrowers and the ability of our borrowers to perform under the terms of their loans and other terms of credit agreements; political instability, acts of war or terrorism and natural disasters; and additional “Risk Factors” referenced in the Company’s most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission, as supplemented from time to time.  When relying on forward-looking statements to make decisions with respect to the Company, investors and others are cautioned to consider these and other risks and uncertainties.  The Company can give no assurance that any goal or plan or expectation set forth in forward-looking statements can be achieved and readers are cautioned not to place undue reliance on such statements, which speak only as of the date made.  The forward-looking statements are made as of the date of this press release, and the Company does not intend, and assumes no obligation, to update the forward-looking statements or to update the reasons why actual results could differ from those projected in the forward-looking statements.

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GUARANTY BANCORP AND SUBSIDIARIES

Unaudited Consolidated Balance Sheets