West Coast gasoline prices fell sharply for the week ending Feb. 22, while the nation's average price remained flat and Midwest gasoline saw a spike higher, according to federal data.

The mixed picture came on a day that oil prices surged higher after a report that U.S. shale output is falling, which some experts said signals a bottoming out of crude prices that have continued to trend lower.

The national average price of a gallon of regular unleaded gasoline increased six-tenths of a cent to $1.73 per gallon. The price is now 60.2 cents lower than it was a year ago, according to data released by the U.S. Department of Energy.

A mixed regional picture emerged as prices continue to decline on the West Coast with a 7.6-cent decline to $2.141 in the region. Without California, West Coast gasoline prices fell 6.3 cents to $1.875. Gasoline prices in these two regions have remained higher that other parts of the country.

In the Midwest, where the region has access to Canadian oil imports that have tamped down prices, gasoline prices increased 8.7 cents to $1.73 per gallon.

Among states, only Hawaii ($2.571), California ($2.317), Alaska ($2.219), and Washington ($2.02) have average gasoline prices above $2 per gallon. At the other end of the spectrum, Missouri ($1.458), Oklahoma ($1.464), and Kansas ($1.492) are under $1.50 per gallon, according to AAA's Daily Fuel Gauge Report.

The average price of diesel fell three-tenths of a cent to $1.983 during the week. Diesel now costs 91.7 cents lower than it did a year ago.