This is just a comment about my experience with Thousand Trails. Some of the details may be off. It has been a few years since I ditched them.
Thousand Trails is nation wide but you have to purchase membership by region. I believe there are 5 regions and each region costs hundreds of dollars. You get 21 days of free camping then I believe its $3/day after that. I got a one year membership free with the RV purchase. I added a second region at a discounted rate to that membership. (mistake)
I ended up using them only a few times. Most were in the middle of nowhere, small sites, very few (if any) amenities, run down, no site reservations (drive around and pick your own) and basically esthetically unpleasing.
Twin Mills in Howe, IN...no sewer hook ups, dump station only. All sites are back in and the sites and roads are lined with trees making it a white knuckle experience just maneuvering around.
Moody Beach RV Campground in Wells, ME...can't comment as it was that unmemorable.
Chestnut Lake RV Resort in Port Republic, NJ...most unfriendly campground I have ever been to. No one waves or say hi. All back in sites. Main road has telephone/light poles in the most awkward places. Makes maneuvering sketchy at best. Best bet to get parked is to find empty sites one in front of the other and just pull thru one to get into yours. Just hope no one parks in the site behind you while you are there. You'll need it to get out. No mosquito abatement in the park.
Timothy Lakes Resort - South in East Stroudsburg, PA...make sure you get the Resort South not the Resort North, your Montana won't fit in the North Resort. Weird thing is though, ALL the amenities are at the North Resort. Cramped quarters, back in sites.
Lake Towakoni RV Campground in Point, TX...truly the middle of nowhere in East Texas. The closest town is Canton. The only thing going for Canton is the flea market and Walmart. (sorry folks who live in Canton, I mean no disrespect) Most run down RV park I have ever been to. Everything is rotting, dirty and dusty. I mention dusty because just starting your truck kicks up a dust storm. Half the 50a site are down. Gullies run through the park for what appears to be flash flood run off.
Outdoor World Williamsburg in Williamsburg, VA...now I will admit that this place was convenient to the Williamsburg triangle. But, narrow roads, narrow sites, back in only, no place to conveniently park my truck.
Yukon Trails in Lyndon Station, WI...another unmemorable RV park except it was convenient to Wisconsin Dells.
I know I have stated in other posts that I don't look for resort amenities when picking RV parks. All I need is a pull thru, full hook up, 50a site. But none of these places met those requirements. All these parks were old and not designed for our big Montanas, but they listed no size limit.
I will NEVER have anything to do with a Thousand Trails RV park again. I would rather stay in a Flying J parking lot.
I know I went off the reservation a bit, but when I read the words Thousand Trails, I snapped.
The opinions and experiences expressed here are strictly my own and in no way are meant to disparage anyone who currently uses Thousand Trails RV parks.
Charlie, I know this didn't answer your question, sorry.