There are many places you can get Propane.. Depending on where you are, OFten the campground has Propane service, however it is a bit like buying a soda at a theater. (Expensive) as a general rule, NOTE Some of the parks I visit the propane preices are highly competitive, but often they are "Theater Priced".
I have seen a number of gas stations with Propane. Flying-J nearly always has it as someone else mentioned.
I like to look for propane suppliers, not retalliers but wholesalers Saturday morning I made a call to Carmichael's Propane in Tekonsha, 2.69 per gallon and open on Sat till 1 PM. (Going price is about 3.and a quarter to 3 and a half just now). Now I do admit Carmichaels is (normally) a bit out of the way and hard to find but not a problem for me,plus by choosing an "Non-Freeway" route I had nearly all 55mph roads to where I was going next, A great excuse to visit Tucker's Produce stand (Good Ruhbarb, it's a pie now and dissappearing fast) and... Well, when I explained to Mrs. Carmichael why I did not need directions, it lead to a nice chat about the farm they bought from my dad. (I said I did not need directions
). Have not been there in 40 years.
The moral of this is to GOOGLE: Propane {zip code} and look for wholesalers Then let your fingers do the walking through the phone numbers, and find out the prices.
Conversely,,, When I'm in South Carolina, the wholesaler is the most expensive gas in town. I go to the ACE hardware if I need gas.
Near Flint, MI> try Parker's Propane. (Another wholesaler) only open m-f though.