There is only one trailhead, so you're looking at an in and out backcountry hike. Sometimes this great outdoors hiking trail gets really dry, so do check for current fire restrictions before you go if you plan to bring a stove or make a camp fire. Horse Mountain Trail is 12.2 miles long; it's longer than many wilderness hiking trails. Horse Mountain Trail has a total elevation difference of 1,359 feet which is about average. Now this great outdoors hiking trail is pretty long, so make sure you bring plenty of supplies. There's not much difference in elevation along the wilderness hiking trail which means the conditions are about the same from start to finish. Of course, this is an overnight trek, 2 days normally, so it's a wonderful thing if your backpack is big enough to do the job.