Exhibit 99.1

FOR IMMEDIATE RELEASE:

Guaranty Bancorp Announces 2011 First Quarter Financial Results

·                  Net income of $0.5 million (before non-cash preferred stock dividends)

·                  Asset quality shows continued improvement highlighted by a 7.2% decrease in classified assets in the first quarter 2011 and a 2.7% decline in nonperforming assets

·                  Continued growth in lower cost core deposits with $57.4 million of additional growth in the first quarter 2011

·                  Capital and liquidity remain strong

DENVER, April 21, 2011 — Guaranty Bancorp (Nasdaq: GBNK) today reported first quarter 2011 net income of $0.5 million before preferred stock dividends compared to a net loss of $1.8 million before preferred stock dividends in the first quarter 2010.  After giving effect to the preferred stock dividends, the loss per basic and diluted common share in the first quarter 2011 was $0.02  compared to a loss per basic and diluted common share of $0.06 for the same period in 2010.

The Company’s net income before preferred stock dividends for the first quarter 2011 of $0.5 million is an increase of $2.4 million as compared to the first quarter 2010.  On a pre-tax basis, the improvement in net income was $3.6 million for the first quarter 2011 as compared to 2010. This increase is primarily due to approximately $4.0 million in lower costs associated with problem assets, a $0.7 million reduction in other expenses and a $0.7 million gain on sale of securities, partially offset by a $1.9 million reduction in net interest income due mostly to lower loan balances.

Paul W. Taylor, Guaranty Bancorp’s CFO and COO, stated, “We are very pleased with progress made in 2011 to improve the core operating metrics of the bank. The net income before our non-cash preferred stock dividends is attributable to the risk-reduction strategies employed during the past two years. As important, we continued to improve the asset quality of the bank while growing core deposits. After a 23% decrease in classified assets in 2010, classified assets declined by another 7.2% and nonperforming assets declined modestly in the first quarter 2011. Our low cost core deposits increased by $57.4 million, or 5.8%, during the first quarter 2011 due to our continued focus on growing our retail and business customer base. Even with the growth in core deposits, the interest expense associated with core deposits actually declined by $0.1 million due to lower rates on our core deposits.  Additionally, we continue to strategically reduce higher cost time deposits. The $81.4 million decrease in time deposits in the first quarter 2011 resulted in a $0.5 million decrease in our interest expense.”

As previously announced, the resignation of Dan Quinn, Guaranty Bancorp’s President and CEO, will be effective as of the Company’s Annual Meeting of Stockholders, which is scheduled for May 3, 2011.  The Board of Directors is in the process of the search for a new CEO and President with the assistance of an executive search firm focused on the financial institutions industry.  Several qualified candidates have been identified and are in the process of being interviewed.

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Key Financial Measures

Income Statement

Balance Sheet

Net Interest Income and Margin

First quarter 2011 net interest income of $14.7 million decreased by $0.7 million from the fourth quarter 2010, and decreased by $1.9 million from the first quarter 2010.  The Company’s net interest margin of 3.42% for the first quarter 2011 reflected an increase of 3 basis points from the fourth quarter 2010 and a decrease of 8 basis points from the first quarter 2010.

The $0.7 million decrease in net interest income in the first quarter 2011 as compared to the fourth quarter 2010 is due mostly to a 12 basis point decline in the yield on loans coupled with a $70.2

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million decrease in average loan balances.  These two items contributed to a $1.7 million decline in interest income on loans.  Partially offsetting this decrease in loan interest income was a $0.5 million increase in taxable investment security interest income and a $0.6 million decrease in deposit interest expense.  The increase in interest income on taxable investments is due mostly to a $25.0 million increase in the average balances of such investments along with a 37 basis point increase in the yield on taxable investments.  The decrease in deposit interest expense was due mostly to a $0.5 million decrease in time deposit interest expense due to management’s continued strategy to reduce non-core time deposits.  The average balance of time deposit accounts decreased by $76.5 million in the first quarter 2011 as compared to the fourth quarter 2010.  In particular, during the last week of the first quarter 2011, a $33.6 million brokered time deposit with a rate of 4.25% matured and was not renewed.  Although this did not have a significant impact on first quarter 2011 results, it is anticipated to reduce ongoing deposit interest expense.  Throughout the remainder of 2011, the Company has approximately $98.2 million of brokered time deposits with a weighted average cost of 2.87% maturing that the Company does not expect to renew.

Net interest income decreased by $1.9 million in the first quarter 2011 as compared to the same quarter in 2010 due mostly to a $5.3 million decrease in loan interest income, partially offset by a $2.1 million decrease in deposit interest expense and a $1.5 million increase in interest on taxable investments.  The decline in loan interest income was primarily attributable to a $303.4 million decrease in average loan volume as the Company worked to reduce its overall risk profile.  Partially offsetting the impact of the decline in loan volume was an increase in the average balance of taxable investment securities by $190.6 million in the first quarter 2011 as compared to the same quarter in 2010.  The cost of deposits decreased from 1.49% in the first quarter 2010 to 1.00% in the first quarter 2011 due primarily to a reduction in time deposit interest expense.

Noninterest Income

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

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The $3.9 million increase in noninterest income in the first quarter 2011 as compared to the fourth quarter 2010 is mostly due to a $3.5 million credit-related other-than-temporary-impairment (OTTI) recognized on a single, non-rated municipal bond in the fourth quarter 2010.  This security was evaluated for impairment at the end of the first quarter 2011 and no changes to the initial OTTI was considered necessary on this bond.  Additionally, the gain on sale of securities increased by $0.5 million in the first quarter 2011 as compared to the fourth quarter 2010.

The $0.9 million increase in noninterest income between the first quarter 2011 as compared to the same quarter in 2010 is primarily due to a $0.7 million gain on sale of securities.

Noninterest Expense

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

The $1.0 million decrease in noninterest expense in the first quarter 2011 as compared to the fourth quarter 2010 is due mostly to a $0.4 million decrease in expenses related to other real estate owned and a decrease of $0.5 million in other general and administrative expenses.  The decrease in other real estate owned expense is primarily due to a reduction in net write-downs on other real estate owned properties resulting from valuation adjustments and sales. The decrease in other general and administrative expenses is due mostly to various reductions across all items of miscellaneous expense including advertising, data processing, communication and loan collection expenses.

The $2.7 million decrease in noninterest expense in the first quarter 2011 as compared to the same quarter in 2010 is due mostly to a $2.0 million decrease in expenses related to other real estate owned as well as a $0.6 million decrease in insurance and assessment expenses. The decrease in other real estate owned expense is due mostly to a reduction in net write-downs on other real estate owned properties. The decrease in insurance and assessment expenses is due mostly to a decrease in our risk category for FDIC insurance assessment purposes, as well as a decrease in overall deposits.  Effective April 1, 2011, the FDIC insurance assessment rules have changed as a result of the Dodd-Frank Wall Street Reform and Consumer Protection Act.  These new rules change the assessment base from total deposits to average total assets less tangible capital. The assessment rates have been lowered to account for the higher assessment base. The Company expects that these new rules will have a favorable impact on FDIC insurance assessments for the remainder of 2011.  Had these new rules been in effect for the first quarter 2011, our FDIC insurance premium would have been reduced by approximately $0.2 million.

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Preferred Stock Dividend

Effective February 15, 2011, a 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 $1.5 million.

Balance Sheet

At March 31, 2011, the Company had total assets of $1.8 billion, which represented a $35.6 million decline as compared to December 31, 2010 and a $195.9 million decrease as compared to March 31, 2010.  The decline in assets from December 31, 2010 is mostly due to a $78.5 million decline in loans, net of unearned discount, partially offset by a $43.3 million increase in cash and due from banks over the same time period.  This loan decline was due mostly to a $45.1 million decline in commercial loans and a $29.6 million decline in real estate loans.  The increase in cash and due from banks is due to proceeds from the reduction of loans being held to fund anticipated reductions in brokered time deposits, purchase additional investment securities and fund future loan growth.

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

Since March 31, 2010, the ratio of construction, land and land development loans to capital has fallen by 28 percentage points to 77% at March 31, 2011.  Similarly, the ratio of commercial real estate loans to capital has fallen by 59 percentage points to 268% at March 31, 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.

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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 29.2% at March 31, 2011, as compared to 25.6% at December 31, 2010 and 22.7% at March 31, 2010.

Deposits, other than time deposits, increased by $57.4 million, at March 31, 2011 as compared to December 31, 2010 and increased by $121.5 million as compared to March 31, 2010.  The increases in non-maturity deposits were primarily attributable to the continued success of our business and retail strategic deposit gathering campaign. We plan to continue this deposit campaign, which includes a variety of different advertising media, throughout 2011.

Time deposits continue to decrease primarily as a result of management’s efforts to reduce the overall level of higher cost time deposits, including brokered and internet deposits. Total brokered deposits at March 31, 2011 were $133.3 million as compared to $179.9 million at December 31, 2010 and $267.5 million at March 31, 2010. In addition to this $134.2 million decline in brokered deposits over the past twelve months, we also experienced a $60.3 million decline in internet time deposits over the same time period. The remaining decline in time deposits is primarily related to the non-renewal 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 $163.2 million at March 31, 2011 as compared to $163.2 million at December 31, 2010 and $164.3 million at March 31, 2010.  The entire balance of borrowings at each balance sheet date consisted of term advances with the Federal Home Loan Bank.

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Regulatory Capital Ratios

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

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 March 31, 2011, approximately $30.0 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 2.25% of the subsidiary bank’s risk-weighted assets.  In addition, approximately $1.3 million of deferred tax assets were disallowed for purposes of computing Tier 1 capital.

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Asset Quality

The following table presents selected 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 $10.7 million increase in other real estate owned at March 31, 2011 as compared to December 31, 2010 is primarily attributable to the addition of $11.9 million related to two similar properties from the same borrower that are expected to be sold during the next two quarters for a full recovery of our cost basis.

The types of nonperforming loans (excluding loans held for sale) as of March 31, 2011 and December 31, 2010 are as follows:

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The $13.5 million decrease in nonperforming loans during the first quarter 2011 is mostly due to the foreclosure on two properties related to one loan relationship with an aggregate value of $11.9 million.  The specific allowance associated with nonperforming loans increased during the first quarter 2011 primarily due to updated valuations and broker opinions on properties that the Company plans to dispose of in an expeditious manner.

The types of loans included in the accruing loans past due 30-89 days as of March 31, 2011 and December 31, 2010 are as follows:

Net charge-offs in the first quarter 2011 were $2.2 million as compared to $14.3 million in the fourth quarter 2010 and $4.0 million in the first quarter 2010.  The majority of the charge-offs in the first quarter 2011 related to a single loan relationship.

In addition to the $12.1 million of allowance specifically allocated to impaired loans, the Company had partially charged-off $10.0 million of the impaired loans on the balance sheet as of March 31, 2011 in prior periods. These prior period partial charge-offs have reduced the specific component of our allowance for loan losses. The general component of the allowance for loan losses decreased to $34.7 million at March 31, 2011, or 3.09% of loans, net of unearned discount, as compared to $40.4 million, or 3.36% of loans, net of unearned discount, at the end of the previous quarter.  The decrease in the general component of the allowance for loan losses during the first quarter is primarily attributable to a decrease in the balance of the loan portfolio subject to a general allowance for loan losses and a declining trend in net charge-offs within the Company’s historical look-back period.  This caused a decrease in our historical loss component of the allowance for loan losses.

The Company recorded a provision for loan losses in the first quarter 2011 of $2.0 million, as compared to $19.5 million in the fourth quarter 2010 and $4.0 million in the first quarter 2010.  The decrease in the provision for loan losses was the result of the reduction in the general component of the allowance for loan losses due mostly to a significant reduction in the level of historical chargeoffs in our look-back period, a decrease in classified assets and a decline in the overall loan portfolio subject to a general allowance for loan losses.

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Shares Outstanding

As of March 31, 2011, the Company had 54,034,095 shares of common stock outstanding, including 2,295,836 shares of unvested stock awards, but excluding 156,567 shares of common stock to be issued under its deferred compensation plan. In addition, the Company had 67,504 shares of Series A convertible preferred stock outstanding, with a liquidation value of $1,000 per share.

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.

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:

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Tangible Equity Ratio

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

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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

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GUARANTY BANCORP AND SUBSIDIARIES

Unaudited Consolidated Statements of Operations