The trail follows the Tongue River upstream. There are several variations once you're up the canyon a ways. Best done as an 'out & back', but some people (wimps)take a shuttle up the paved highway to the top and ride down.
How to get there:
The Dayton turnoff is about 10 miles north of Sheridan off of I-25. The road to the canyon is the road to the right directly before you cross the bridge over the Tongue River. Follow this road into the canyon for about 4 miles to a small campground where the trailhead starts.