For camping inside many National Parks, yes. You could camp outside the parks and drive in to tour. See this chart:
http://outdoorsrvmfg.com/wp-content/uploads/2017/11/National-Park-Trailer-Length-Chart.pdf
Winnebago 2101DS TT & 2022 Chevy Silverado 1500 LTZ Z71, WindyNation 300 watt solar-Lossigy 200 AH Lithium battery. Prefer boondocking, USFS, COE, BLM, NPS, TVA, state camps. Bicyclist. 14 yr. Army -11B40 then 11A - (MOS 1542 & 1560) IOBC & IOAC grad