On February 28, 2011, the U.S. Department of Transportation Office of the Inspector General (DOT OIG) released an audit report on revenue use by the City and County of Denver. The audit principally concerned Denver’s sale of property that had been used for the former Stapleton International Airport that closed in 1995. The DOT OIG found that the FAA failed to ensure that Denver received fair market value for properties sold to a master developer and failed to protect against the diversion of airport revenue for non-airport purposes.  The FAA did not concur with OIG’s findings.