Prices of a gallon of regular unleaded gasoline in Utah hit their record high of $2.91, thanks to ethanol-related fuel-supply problems in key East Coast markets and a typical run-up in prices before the Memorial Day holiday, according to a AAA Utah report released Tuesday.

That record high was last reached in Utah on Sept. 10 in the aftermath of Hurricane Katrina.

Utah's average price of $2.91 is 57 cents higher from a month ago and 63 cents higher than last year. Nationally, gasoline prices are at $2.93, up 24 cents from a month ago and 77 cents from a year ago. Gasoline prices in Provo jumped 59 cents a gallon from April to $2.88.

"Utah enjoyed the lowest gasoline price in the country just a month ago," said AAA-Utah spokeswoman Rolayne Fairclough. "Since then, the price of gasoline has steadily increased. Today there are 21 states with a price higher than Utah."

Ethanol-related fuel-supply problems, which hit the mid-Atlantic and parts of the Northeast and Texas, and the recent spike-up in crude oil prices have contributed to sharply higher gasoline prices. The situation has gotten worse this year because refiners in key East Coast markets are struggling with the conversion to ethanol from the MTBE additive, which is found to pollute the environment, Fairclough said. Once the switch to ethanol is completed, gasoline prices are expected to level off.

"The refineries need to secure supplies of ethanol, which is an alcohol-based fuel, and they also have to figure a way to mix it at the retail stations," she said.

"Ethanol is corrosive on metal. So the retail stations have to pump their gas tanks dry of gasoline first, clean and seal them so the ethanol-based fuel doesn't get in contact with the metal. Also, ethanol can't be transported on pipelines. It has to transported by trucks in special tanks."

Strong demand in rapidly growing economies in China and India and unrest in oil-producing countries are other factors keeping crude oil prices, and gasoline prices, high, she said.

Fairclough also cited a typical run-up in gasoline prices before Memorial Day, which marks the start of the summer driving season.

"The run-up we have all experienced at the pump has been nothing short of painful," Fairclough said. "There may be some relief after the switch over is completed and the typical drop in prices after the Memorial Day holiday."