The Tax Foundation says states tax fuel in several ways, including sales taxes, per-gallon excise taxes collected at the pump, taxes imposed on wholesalers (which are passed along to consumers in the form of higher prices), and a variety of operational taxes, such as underground storage tank fees, that are often charged to the retailer.   To that end, they added up all different taxes & fees to calculate a total tax rate on gas for each state – see interactive map below.

“Though gas taxes are intended to serve as user fees and pollution deterrents, they vary widely across states.”