Utah gasoline prices are finally dropping below the national average, ending a nearly four-month stretch of higher-than-average prices that resulted in a state investigation.

According to AAA, the average price of a gallon of regular gasoline in Utah on Monday was $2.28, 1 cent below the national average.

From mid-August through early December, Utah gasoline prices exceeded the national average, on some days by more than 40 cents a gallon, according to data provided to the Deseret Morning News by AAA.

The state's higher-than-average prices led to an investigation in September by the Utah Department of Commerce, which concluded that gasoline retailers in Utah were gouging consumers but were not breaking any state laws.

Francine Giani, executive director of the Commerce Department, led the investigation and said Monday that Utah's falling gasoline prices are good news for consumers.

"We hope that the trend continues downward," Giani said. "I think that there are some questions that still need to be answered long term. That is, how will we handle the increased demand needs of our ever-increasing population?"

During the first 11 months of this year, gasoline prices in Utah on a daily basis exceeded the U.S. average 51 percent of the time — 171 out of 334 days. In January, Utah's gasoline prices were the lowest in the nation. By September, Utah posted the fourth-highest average gasoline prices in the country.

The biggest difference between average prices in the United States and Utah occurred on Sept. 25, when a gallon of regular gasoline in Utah averaged $2.80, 42 cents higher than the national average of $2.38.

At the beginning of this year, Utah's gasoline prices on a daily basis were often 10 cents to 15 cents lower than the national average. And on April 20, gasoline prices in Utah averaged $2.45, a discount of 38 cents compared to the national average of $2.83.

But as the Memorial Day holiday approached, prices rose above the national average and stayed there for the entire month of June. Through July and the first half of August, Utah prices again fell below the national average, only to rise again prior to the Labor Day holiday weekend even as national gasoline prices were plummeting. Utah's highest recorded price was on Aug. 21, when the average reached $2.99.

John Hill, executive director of the Utah Petroleum Marketers and Retailers Association, said Utah will continue to see wild fluctuations in gasoline prices unless more product is brought into the state.

"We need more refined product," Hill said. "If we had a pipeline with refined product coming in, it would increase the supply and affect prices. It should bring us more in line with the national average and probably below it."