Wondering if any stunts or work can be done on the trails that are not open to disc golfers and skiers, like Randy's, Frank's, Annie's, etc.
Sure stunts can be built. Reid just built one the other day. What kind of work are you hoping to do? Run it by Jeff (mjpo) and I am sure something can be worked out.
I'm pretty sure he knows stunts can be built, but what is meant by "trails not open to disc golfers and skiers"? I don't think any of the advanced MTB loop is open to them, so that's the place to build.
Yes, it all needs to be cleared with Jeff (the Trail Coordinator, or TC, for those who don't know) ahead of time, and certain rules need to be followed, particularly that you can't use any lumber that isn't pressure treated and it can't be smaller than 2" dimensional. By dimensional, it means the stated size. In reality a 2"x4" is only something like 1.5" x 3.5", if you can believe that, but it says 2", so it qualifies. Also, apparently there are special resistant screws that you should use for treated wood. Some of Burchfield's older stunts do not follow these rules, but these are the current rules. Also, no articulating features, nothing should be intended to move while the rider is on it. For example, this rules out teeter-totters. And hamster wheels. Carousels.
Each stunt needs to have a bypass and ideally the bypass should be the main trail, so that a rider has to purposely go off the main trail to ride the stunt.
Then there is the obvious rule about not making it unsafe. I aim, though may not always succeed as much as I would like, to make the entry difficult if the exit is difficult. I don't want anybody nonchalantly cruising up onto something and finding a nasty surprise at the end.
People are supposed to walk any new stunt before they ride it, but I think people assume that if something is there - it's safe to ride it.