Gas prices have risen over six cents in the last week in Montana. GasBuddy.com Petroleum Analyst Will Spear said prices have spiked because it’s the time of year where all of the supplies for gas are almost completely switched over to the more expensive summer blend.

"The good news is that we've started to slow down slightly, I mean, still six cents off in a week for Montana, but still staying below the national average right now at $1.96 in Montana, with the national average being $2.04," Spear said.

Missoula was no exception to the increase, where prices jumped up seven cents. With summer approaching, Spear said prices should continue to go up.

"In the last month, it's probably been about 26.5 cents off so there's definitely been a pretty big price hike that we've seen in the Missoula area," Spear said. "Prices kind of just continue to have some upward pressure because of all the demand that the summer driving season brings, with these low prices that we're seeing adds more demand to what we've been seeing."

Prices in neighboring states like Wyoming and Idaho also went up an average of 6.25 cents, with $1.97 per gallon in Idaho and $1.92 in Wyoming.