Hey, I live in Western Maryland (Frostburg) and am looking for a decent rifle range.

I typically go to the range in Savage River State Park, but their range is too small.  About 90 yards from bench to dirt berm according
to my simmons range finder.

I would like to shoot at the very least 100 meters, if not 200 or 300m ideally.  Occasionally I might shoot in the natural woods, but I don't know how legal that is, and I don't
want to end up getting in trouble.  I'm dumbfounded that in such an open, mountainous area, noone can establish a public range that allows one to shoot past 90 yards??

I've seen large tract of farmlands that extend like 4-500 meters at least. If I owned said land, I would shoot on it at my leisure. How the heck do people zero, or atleast confirm hold-overs for their rifles beyond 100 yards if there is no range at which to do so? Hunters don't ever take game beyond 90 yards?