We chose to make a loop by following Horton Trail along Horton Creek to the Spring, then following the Highline Trail South and returning to the trail head via the Derrick trail.
Horton Spring is beautiful, the water literally erupts from the side of the mountain. The forest is lush and make this hike a worth the trip. There is water available up to the Spring, but none is available for the rest of the loop. I tried the water at the spring, and it taste good, but be sure that you use a water filter. Most day hikers will turn around at the Spring and retrace their route back to the parking lot; however it is worthwhile to complete the loop which can be made by following portions of the Highline and Derrick trails.
Highline trail cross the mountain through the forest and is energy consuming in several spots and should be considered strenuous in difficulty. Much of this route offers wonderful vistas of the surrounding area. We spot couple of deer and a lot of squirrels. Approx 2 miles south of the creek the Highline intersects the Promontory Butte trail from the East.
Derick trail this time of the year is hot and not spectacular. The hike down was very rough over exposed, loose rocks and it was not a pleasant walk.
Both trails are marked even though the in some portions of the trail the marks were missing, because of the forest cleaning.
I have measured this loop to be approximately 9.6 miles, although other authors report it upwards to 8 miles.