The worst may be over for drivers in Michigan and other upper Midwest states who have been grappling with the highest gasoline prices in the continental U.S.

Analysts said Tuesday a major refinery is back online and another is on track with a major reconfiguration. The refineries’ issues are blamed for high gas prices in the Great Lakes region.

The average retail price of unleaded gas is $4.20 in Michigan, higher than anywhere else except Hawaii.

Tom Kloza, chief oil analyst at GasBuddy.com, says the worst is over and he doubts Midwest residents will continue paying $1 a gallon more than some parts of the country. He says wholesale prices dropped 20 cents per gallon in the last day, which should lower prices at the pump.