Miramontes states in his guide “this rock boasts the longest approach” in Joshua Tree. Having covered most all routes within my grade range in both South and North Wonderland, I would have to say this statement is accurate. The cool thing is that you can hit Bighorn Dihedral (the main objective on Suicide Horn) as a complete (downhill) hike through the park. In other words by carpooling you can start at the Boy Scout trail head off of Park Blvd and hike all the way through to the trail head for Rattlesnake Canyon in Indian Cove. Two routes that should not be missed for this much hiking effort are two of my favorites in the whole park, Big Horn Dihedral (5.10b) and Firewater Chimney (5.10b). Both receive three stars in Miramontes guide and deserve it. Only two 5.10b routes in his guide get higher marks, Illusion Dweller and Figures on a Landscape. Firewater Chimney is fully bolted, Bighorn Dihedral is all trad. Walk off Suicide Horn Rock to the east. South facing routes.
Miramontes guide has this hike as 4.5 miles to Suicide Horn. Park at the Boy Scout/Willow Hole paved trail-head off of Park Blvd. Hike due north and follow the main trail as it bends left (approximately one mile). Take the marked (2016) right fork for Willow Hole (approximately .25 miles). You will now be heading for Timbuktu Towers straight ahead, you will pass the big face of East Siberia on the left. Miramontes speaks of an old miner’s road. I never saw anything resembling a road. Before you reach Timbuktu, look for a cairned (2016) trail on your right. Follow it into a wash. The wash curves left into a large sandy bottom. Continue following the wash as it takes a sharp right into Willow Hole which is comprised of tons of vegetation and water most of the year. Continue east through the marsh and follow the drainage down as it narrows through boulders, etc. In short order, the drainage opens up and comes to a perpendicular wash. Turn right and right again to hike in front of the southwest faces of Dunce Cap and then Suicide Rock. Scramble up to the base of the obvious right facing dihedral for Bighorn. If you do not back track south to hike below the west face of Dunce, you will either end up having to scramble 5th class up the east side of the formations or hike all the way around their southeast end. To descend to Rattlesnake Canyon, head back north on the previously mentioned perpendicular wash through a notch. Continue north until you reach Valley of the Kings. Turn right and scramble down and around the northwest corner (left) of the Helmet into the valley proper. Turn left and scramble down a boulder drainage to Rattlesnake Canyon. Turn right and follow Rattlesnake Canyon out to the paved trail head. I am just guessing this is approximately a 7 mile trip in total.