Los Pinos/Espinosa Green Sticker Route
This route is a loop of four separate tracks west and northwest of the Corral Canyon OHV Area. It is called a green sticker route but is open to all vehicles. The official maps show the road as suitable for 2WD low clearance vehicles but don't believe it. High clearance is required and some points may require 4WD and low range.
Starting at Four Corners (the parking area where the four paved trails meet) go northwest on Los Pinos Road. This goes 4.1 miles to Espinosa Trail. Los Pinos Road is paved to the lookout tower. After this it is very rough and rocky but it can be traversed with a 2WD high clearance vehicle if you pick your way between the rocks and ruts. Espinosa Trail branches off to the left at a large turn-around area. About 200 yards down Espinosa Trail there are a couple of serious ruts just past the oak tree. A 4WD crossover may make it with a skilled driver but something with extra clearance and a low range may be needed to get past this point. There are some other spots that may require 4WD and low range along Espinosa Trail. Espinosa Trail meets Corte Madera Road after 3.3 miles. Corte Madera Road is easy with a 4WD crossover with the exception of a major rut about 0.5 mile south of Espinsoa Trail. This is definitely passable (as of 5/4/13) but takes a little planning and extra steam going uphill (north). Corte Madera Road goes 4.0 miles to Skye Valley Road, Which is suitable for high clearance 2WD vehicles. After about 1.8 miles Corral Canyon Road splits-off to the left (watch for sign in the rock bundle). This goes 4.1 miles back to Four Corners and is mostly easy for a 4WD crossover with some rough spots that aren't too bad. An alternate route at this point is to continue on Skye Valley Road past Corral Canyon Road, around the Corral Canyon OHV area for 7.9 miles (from the start of Skye Valley Road) back to Four Corners.
If you are on a single-rider vehicle you can also take Spur Meadow Cycle Trail from just north of Corral Canyon Campsite to the hairpin turn on Los Pinos Road north of the lookout tower.
Most of this loop can be traversed with a 2WD high clearance vehicle except for Espinosa Trail and the northern end of Corte Madera Road.
Difficulty: very easy (0.5) to moderate (3), difficult (4) on Espinsoa Trail.