It's trail we developed and built, on invitation from the owner who's a farmer who races, and had this ridgeline he wasn't utilizing. . .
Private land is great.
You don't have to worry so much about state rules and regs. You can design and build the trail for bikes, rather then taking over a trail formerly used by skate-skiers or llamas or something. However, there's now way to keep it as rideable land forever - who knows what the owner may have to do, or if the owner passes on, what the inheritors will do. You haven't told the whole story though. Or go in with the local land managers and assist them in buying it with matching funds or labor.