Tricks to keeps rodents from destroying TC

I 'm buying some land in the mountains and would like to leave my Lance on the ground for periods of time to stay in while there. Also, leave it there unused for a few weeks at a time.
The land is pine trees and sage brush and has lots of squirrels and I'm sure mice and rats.
I could make a hard pack gravel base to set it on but what are some good ideas to keep the rodents from getting in and chewing things up and building nests?
I've heard Irish Spring soap works. Maybe moth balls?
I've seen Comet used to keep ants away, wonder if that works for rodents?
Any ideas are appreciated.