On my way home from work today here in Wasilla, Alaska I saw a pickup truck, it was covered with green graphics saying it is running on natural Gas only, a promo truck I believe.
I wanted to convert my Silverado to Ng this year but thought Alaska would be years from getting NG vehicles, now I can see getting one.
And a steam powered swamp buggy....(which I am building but has a diesel in it)
NG is probably the most abundant fuel right now and cheap, worth considering. Your swamp buggy sounds like a fun project!