How do I obtain permission to use the park as a rest stop for cyclists participating in a group ride on the IHRT? Would be only for 2 to 3 hours or sooner depending on when the last rider returns to the trail.

A few hours should be good. Up the hill where the boaters park there's a covered picnic area. That would be good for YA'LL.

Depending how may cyclists there is i would just go ahead and go there for a break. I have seen may bike riders there. There is also a nice place to rest at the end/beginning of the rail trail in indian head. Otherwise google the park and the info shouldnt be hard to find. It should have a website with info.