So what part of WY were you in for this? I've seen spots like that near Guernsey, especially near the hard rock mines. I looked at some land there some years back that were old open faced mines and thought that renting the vertical walls out would be an interesting pasttime.
From the color, though, I'm guessing farther west, like the Lander area. Although there are probably some good climbing areas up near Sheridan and the Big Horns.