With proper planning you can get a big rig to a lot of National forests and state parks. We tow a 35 foot TT and have had no problems getting into parks that we visit here in WI. Going out West it seems to be more of a challenge but we still try to stay out of the private parks when visiting out there (and mostly do). I think if I lived out west I would be a little more comfortable pushing the envelope but don't want to risk it when we just have a few weeks. With two kids and as much as we go I like the space of a 35 foot TT but down the road I would like to shave about ten feet of the length which would open up a ton more sites to pick from.