This is just a few miles from Spearfish, but can be a bit tricky to locate. Read my Community Caves post for detailed directions.
Do yourself a big favor if you plan on hiking this in the winter or early spring, buy some really good spikes like Kahtoola MICROspikes Pocket Traction System. You can thank me later. The first time I went up there in the winter, the trip down was scary. The top portion of the trail is like a sheet of ice. With spikes it is simple to walk up and down. Without you look like a greased pig running on a linoleum floor.
Caution: on warm days large chucks of ice will fall, so just watch out for that .
Here is a video I shot. Either this will motivate you to climb up there or serve as a substitute.