The unfortunately named Negro Bill Canyon Trail is a four-mile out and back on BLM land (=dogs are welcome!) just outside Moab. The hike ends at a large natural bridge–the sixth-longest natural rock span in the US. A few rappellers were descending from the bridge as we arrived which Bugsy did *not* understand The hiking-only trail follows a clear stream the entire way, making it a great option for water-loving dogs like Bugsy. The trail was full of happy dogs, in fact, and the wide and shallow swimming hole in a sunny spot not far from the parking lot was like a preschool playground. We (and especially Bugsy) enjoyed the hike enough to do it one and a half times in three days.
And for your post-hike reward: stop at the pull-off along the road heading back to Moab for a picnic with a stellar view of the Colorado River: