After doing Headquarters Canyon I decided to hike Surprise Canyon while I was in the neighborhood. The kids opted to stay at the trailhead and listen to audiobooks so I just ran it by myself.

There are no narrow sections but the Canyon is scenic (though short). The top of the canyon ends in a large talus/boulder field. I scrambled part way up the boulder field but didn't go to the point where I couldn't go any further. If you were really, really determined there might be more to explore, but with the kids waiting for me at the trailhead I didn't feel like working that hard.