Length restrictions for single or towed combination rigs have come up before but here's a few more examples. Pity there's not a uniform standard for regulations and signage across different jurisdictions to reduce confusion when conditions warrant something non-standard. The various combinations of individual vehicle length, combination length (tow vehicle and vehicle or trailer being towed), basic width of either, or total width incuding mirrors all combine to determine what sort of RV you want to buy or where you can go after you have one.
The week before Thanksgiving, we again joined a group of friends at Furnace Creek campground in Death Valley National Park who either tow SUVs (mostly Jeeps) behind motorhomes or still drive them and tent camp like we still do with our '03 Jeep Rubicon. Access to this and all major campgrounds in the park is pretty much unrestricted, though flatlanders will be alarmed by the steep mountain grades if approaching from the west. Just downshift when needed and, anywhere in park, watch for bicyclists or stopped vehicles. But, if you want to see Dante's View (well worth it), a sign states, "LENGTH RESTRICTION, 25 ft. Maximum Length, No Buses / RV's / Vehicle Combinations", as the parking lot at the view is small. I would imagine a true Class B would be OK despite the "No RV's" wording but might depend upon the level of literalism of someone with a citation booklet, and a short Class B+ (Class C) like a PC would probably not be acceptable due to width. So, use your toad (towed?) or get a ride. Another restriction is on the road to Wildrose Campground on the western side of park. Due to sharp curves combined with narrow width pavement and no shoulder, signs state that the 25 foot length limit is for the total length of your combination, meaning a trailer is OK but it would have to be a short trailer behind a Jeep or small car, or a PC no longer than a 2351 or 2400 and not towing anything. I did call once and ask whether a 26 ft. motorhome would be cited and while it sounded as though no one is regularly patrolling with a tape measure there, should a collision occur, I'm sure there'd be legal repercussions. Up the steep, rough gravel road east of the charcoal kilns (east of Wildrose) and towards Mahogany Flats campground, no towing is allowed due to the road being too narrow in places to risk two vehicles towing meeting each other and one having to back up (uphill has right-of-way). Sportsmobiles, Provan Tigers, and a few campers are all you'd find up there, with all of them having contents shaken about.
A trip to Kings Canyon and Sequoia National Parks will show you various length restrictions (I think 22 and 24 feet), and some side roads also set rather narrow limits based upon width including mirrors. Some maximum lengths are recommendations, others are prohibitions, and some vary seasonally, based on traffic projections. "Going to the Sun" highway in Glacier National Park must also be studied before a trip. Some tunnels in Yosemite would be a worry for certain RVs. Zion NP tunnels are now tightly controlled.
So, before we buy and before we go, a bit of online review of National Park Service maps and guidance is always a must.
If anyone has specific questions about Death Valley, ask, and I'll start another thread in the "Adventure Anywhere" part of the forum.