Today I drove through Bighorn Canyon in southern Colorado looking for, what else, Rocky Mountain bighorns. I didn't see any. (Plus I'm having electrical problems with my car and my Sirius radio is currently unavailable, which is not fun on a long drive.)
However, a couple days ago in Custer State Park, South Dakota, I saw nineteen (19!) bighorns, including a herd of 12 ewes and lambs on the lawn of the Norbeck Visitor Center, and a group of seven rams grazing four miles to the west. Here's one of the rams. Click on the image for a larger version.
Photos from this trip were included in the Autumn 2008 gallery.