While camping on top of the Mogollon Rim, we decided to find our way down to Horton Spring. This is the same trail that's a portion of GPSJoe's "Horton Super Loop" hike. The trailhead is well marked and the first 1/4 mile is very well defined and easy to follow, there are portions lined with 4" thick downed trees, and then rocks.
But when you start the steep descent, the trail becomes far less obvious. Thank goodness for cairns, they were about every 50 feet during the top part of the descent. However, they get further and further apart, and the only way to know you're on a trail at points is by the trampled down grasses. It looks like no one goes UP this trail, all the grass is trampled towards the downhill angle.
At about mile 1.5, and probably 300 feet above the canyon floor, we lost the trail completely - No more cairns (that we could find), and no obvious signs of travel. Being unfamiliar with the trail and not seeing any signs of a creek or springs, we decided to call it a good journey and find the 'destination' (the spring) by hiking up from the Tonto campground tomorrow http://hikearizona.com/photoset.php?ID=11622
. So we turned around and got a good workout climbing back out.