You'll get in a lot of public parks with a 35-37'. With our 40' we've used Yellowstone, Grand Teton, Big Bend, Glacier, Canadian Rockies - Banff, Jasper, Alaska, Zion, Rocky Mountain, Bryce and many others. We also fit in national forest campgrounds, state parks, Corp of Engineers, county and city parks. You'd definitely fit in RV parks.
Full-timed for 16 Years . . .
Traveled 8 yr in a 2004 Newmar Dutch Star 40' Diesel
& 8 yr in a 33' Travel Supreme 5th wheel