other than the usual suggestions like storage yards, boat yards, etc there isnt' any real answer. We all seem to have to figure that one out on our own. Its the million dollar bus question, and one folks should really think hard on before buying a bus.
I lost my first bus in an expensive legal battle due to thinking I could just go and get a bus and have it. I actually thought I lived in a free country when I was young! lol
Hit up friends who have property, look into buying some cheap land or a cheap lot somewhere tolerant.
Try to find two or three places you could definitely store it. I've had to move mine a few times. Being at someones mercy sucks. I'm buying a lot in out in the boonies so I can have buses and burn stuff!