This section of Denver Color lists links to travel centers and gas stations that keep the tanks in the Mile High City full.
Denver Gas Prices (www.denvergasprices.com) - review Powered by GasBuddy, DenverGasPrices.com lists local gas prices. The program uses local volunteer gas price spotters. The site includes forums for sharing gas saving tips.
Maverik Country Store (Profile) Maverik is a chain that combines fuel centers and a convenience store. They have multiple locations in the Denver metro.