Here in Liberty MO we have four sources, Phillips 66 top tier sold by their stations and the Quick Trips in the KC metro area. This comes from a local Phillips distributor called Zarco 66. Sounds like a holding company to me.
Another choice is non top tier sold by the Casey's General Stores and Hy-Vee grocery stores. Comes from same source in Iowa. Hy-Vee has 91 octane non ethanol. It has that old time smell.
Another choice is Sam's Club. Who knows it source. Might be Murphy's. Top tier yeah/nay?
BP has one station. It has the luscious Amoco Ultimate 93 octane. It really smells like gasoline. IMO the sleeper of premier fuels. The closest Shell is about 12 miles away. Sinclair came and went.
There is just no Exxon, Mobil, Chevron. Sunoco ect. Choices are narrowing.