I’m not sure if it’s all fenced but the entire thing (including the road) is on private land, so walking around it is trespassing.

There’s only 1 road going there and it ends at the visitor’s center, and impact crater walls are higher than surrounding terrain, so unless you get past the visitor’s center all you see is a hill.

Yes, the entire crater is surrounded by a fence and on private property. It’s not worth the admission price just to see a crater imo. It’s a national landmark, not a national/state park. Unfortunately that designation means very little other than the owner being eligible for some tax breaks so long as they keep it preserved. I find it insane that such a landmark wouldn’t be taken over by the state for preservation.