My Honda Rancher 4x4 would do wonderfully up there.

EFI for easy starts in higher elevations and cold weather
420cc's is adequate or better
SRA for stability on hillsides
big enough for short trips with a rider
small enough to be nimble in thicker woods and narrow passes
uber-reliable

Your place sounds fun......
Can I come ride? Huh? Huh?.......Can I? Can I? lol