We did a month long trip of the western national parks pulling a toad last year and getting fuel was a non issue. We used the Gas Buddy app to plan our fuel stops based on price and access. Nancy (navigator) would use Google maps to get the lay of the land before we committed to a particular station. If I could do it with diesel it would be a piece of cake for a gasser.
We pulled our toad over the hog's back of Utah 12. It did have my undivided attention but it was no problem.
We put a hundred miles on the toad in Yellowstone in one day alone.
Make your reservations early. Arches is awesome but the camping area is small and sells out early.