The national average price for a gallon of diesel jumped 7.5 cents to $3.055 for the week ending Aug. 6, according to the Energy Information Administration. This marked the first time since the week ending Oct. 23, 2005 that diesel averaged above the $3 mark.

Prices went up in all regions, but surged the highest in the Rocky Mountain region, up 15.6 cents to $3.208—dethroning California from its dubious honor of being the most expensive region in which to fill up. California prices were the most stable, rising a relatively modest 3.7 cents to $3.13. California was the second most expensive region in which to purchase diesel.

The cheapest region in which to fill up was the Gulf Coast, even as prices rose 6.3 cents to $2.988.