“From a supply perspective the Rockies gasoline inventory has increased by 17% in the past month while the U.S. inventory increased by 11% over the same period. At the same time the region’s refinery output during the month of December was 95.2%, while nationwide (including the Rocky Mountain region) refineries operated at 90%. Today’s report from the Dept. of Energy has the region’s refinery utilization rate at 96.9% , so it really doesn’t get much better than that,” he noted.

“Consequently, 60% of gas stations (2,848 out of 4,712) in the Rocky Mountain region have gas below $3 per gallon. Only 24 percent of stations in the rest of the U.S. are below $3,” said Gregg Laskoski, another senior petroleum analyst with GasBuddy. (For all 50 states, 26.1% are below $3 today.)

How long will the party last? “The logistics of the region create a lag effect that keeps gasoline price trends there about two weeks behind what we see in the rest of the country,” says DeHaan.