getting a 36 ft tt

Lots of places have succumbed to the CYA temptation that today's litigious society has foisted upon us.

Someone who has the legal right to buy a 36' TT but might not have any clue how to drive or spot the trailer must be protected from their own stupidity by warning them ahead of time that the site is old and smaller and their feeble brain and talents won't allow them to get in without smashing it or someone else's unit.

A good friend of mine has a huge 5er and has put in plenty of 'small' sites without any issue at all.

There's ways to work around it. Maybe stay outside the park and drive a bit to see the park. There's 1,000's of people with 36' 5th wheels that run all over the country and see what they want to. Not much different IMO.

COE cg are usually able to take very long RV as well. Forest Service sites seem to be even worse than NPS/NM sites at least in some areas.

You don't have to limit yourself to private campgrounds. We had a 36' travel trailer and stayed in numerous State Parks. Just make sure when looking at sites you have entered the length of your trailer so the sites that are too short are eliminated from your search.

so private campgrounds it is lol!

LOL , absolutely. Almost all NPS CG were built many years ago when long RV's were never even thought of. Some back in the 1930's by the CCC. I looked into this and found that 30 ft is the point when you'll start finding it difficult or impossible to find a spot inside a park. Chihuahua NM limits campers to 25ft IIRC. And they aren't alone. Yosemite only has a few sites for longer rv in the valley. And you can forget Touloumne CG.