Wild Loop, with access to the keyhole, is for hikers only.
This trail picks up at the northern end of the Hidden Valley Trail. Veer right (to the left is closed to bikes) and climb a steep hill with a few switchbacks, water bars, and one or two significant rock obstacles. Most riders will have to push up a few of the technical sections.
3/4 of the way up the climb the trail splits. This is Hunter Loop. Stay to the right (hikers and horses to the left) and the trails rejoin in 1/2 a mile or so. The trail then turns into a gradual climb and the rocks begin to dominate the trail.
The trail splits again at around mile 2.5. This is Laughing Horse Loop. Both trails have many rock sections that begin to resemble something from a Martian landscape. The west half of the loop, while challenging, is rideable by most, while the east half of the loop is black-diamond difficult and will require most riders to push a few sections with large rock drops and obstacles. The trails meet back up after 1/2 mile or so and then climbs to the top of the ridge. From here you can continue onto the Blue Sky Trail and Indian Summer Trail.