Yep. A one-mile hole in the ground!

Drove up here after Fort Rock and Big Hole. I agree that there is zero signage to lead one here, so good mapping is necessary. It's bumpy, but the drive around the rim is easy enough. The drive to the bottom is quite exciting, but my stock Crosstrek made it with no real drama. The road profile is a real roller coaster. Reminded me of being in six-foot ocean swells in a 12-foot boat. Short wheelbase is what is required here.

I found a nice campsite at the North end and spent a very quiet night here. There are maybe eight or so sites around the rim for camping. I think three were occupied that night and one guy at the bottom camping.