Hike to Horton Springs on the Mogollon Rim in Arizona.
This is a great hike to escape the Phoenix heat in the summer. The trail runs through a pine forest and is easy to follow. To find the trailhead from the parking area, cross back across the small paved bridge and hike towards the campground. The signed trailhead will be on your left. For the first mile or so, the trail skirts a bubbling creek. There's a good climb toward the end of the hike, with a number of switchbacks that gains most of the hike's elevation. Eventually, you'll reach a signed trail that intersects with the Highline Trail. Turn right here (JCT 1R on the map) and hike the final few hundred yards to the spring. Fill up your water here and enjoy the day. Be sure to explore the spring area, as there's more than one spring. When ready, return the way you came.
