Not just the west states and the mid-west states but also the east states.
Ain't gonna see FAKE ASS "side of the road" claim of a dollar more per gallon when using credit cards:
In New York, gas stations are legally required to clearly display the higher price for credit card purchases and offer a cash discount, or display both prices. This is because credit card issuers charge businesses a fee of 1–4% to process payments, which merchants can pass on to consumers.