The gentle rollback comes after Hurricane Harvey shut down refineries in Texas and sent prices soaring in late August and early September.
In Rapid City, the average price for a gallon of gas is $2.32, according to Triple A. Statewide average gas prices have fallen three cents per gallon, according to GasBuddy.
AAA Michigan surveys daily fuel prices at 2,800 gas stations across the state.
As the Gulf Coast and Florida slowly recover from Hurricanes Harvey and Irma, AAA says many Americans are turning their attention to Hurricane Maria.
Nationally, gas in San Francisco was the highest in the contiguous U.S.at $3.18 a gallon. The national average has increased 19.6 cents per gallon during the last month and stands 34.7 cents per gallon higher than this day one year ago. This time previous year consumers were paying an average of $2.09 per gallon.
"If it weren't for the recent hurricanes, gas prices would be about 25 cents lower", said Mark Jenkins, AAA spokesman.
Prices are finally returning to normal after supply and demand have begun to balance out. Prices are expected to "slowly drift lower as inventories slowly improve", GasBuddy.com senior analyst Patrick DeHaan said. Companies have reported that roughly two dozen storage tanks holding crude oil, gasoline and other fuels collapsed or otherwise failed during Harvey, spilling a combined 140,000 gallons of fuel, according to an Associated Press analysis of state and federal accident databases.
But fuel prices are stubbornly clinging to higher costs, despite the slow declines.