Where I live, Tucson. Now most gas station have it, though there’s still some that don’t, but even the ones that do it’s generally 1/8 of the pumps.
If most of the gas stations have it, how is it not readily available?
I don’t consider learning which local station lack a diesel pump the same as not available. And I have commonly found that a station that sells diesel, has a big sign out front with a diesel price. It just is not that hard to find. Learning to look for the different colored handle is not that hard.