Honestly, MGM looks rad and I would love to check it out, but I wouldn't be a turd about it. The biggest thing with trails is cleaning your trash, fixing your damage, and helping make it BETTER than when you arrived.
If you put in work most locals are cool with that.
As to the location being posted or pics/videos-up to the main builders and locals. ASK about photos etc being posted. Most of the time finding a random set of trails is due to exploration. Back when I started we found some in north Burnsville or Apple Valley because of a kid I knew who lived near them.
Ours were blown up by a couple kids not respecting our request to not have them tell others. 3-4 of us were riding and building and some kids rolled in and saw, then told their homies. It expanded our scene for a bit, but then those kids started having fires, burning furniture, and doing drugs out there. We found used needles and all kinds of junk. They were trashed. Plowed right when they were getting fun.
I just hope when I get a little more financially set I can look into my next house and some land so I can build some jumps for me and my son.
"Hey anybody ever make that mistake like right when you wake up in the morning and you believe in yourself?" -Kyle Kinane
"BIKES!" -Tom Segura