The average price of retail gasoline in Wyoming increased last week by 1.2 cents per gallon. WyomingGasPrices.com says  Prices on Sunday were  12.8 cents per gallon higher than the same day a year ago and 20.8 cents a gallon lower than a month ago. The lowest gas price in the state was found in Cheyenne at $2.61 a gallon. The highest price in Wyoming was $3.39 a gallon.