If you want to rent equipment to use on this day, try Sport Chalet in La Canada. It's open until 9:30 p.m. on Friday, and opens on Saturday at 9 a.m.
Horse Flats is located in the Angeles National Forest. From Los Angeles, follow Highway 2 north until it becomes the Angeles Crest Highway. Continue 29 miles (will probably take close to an hour) to the intersection with the Santa Clara Divide Road (Road #3N17) at Three Points (watch for the sign). Turn left and drive about 1 mile to the Christian Camp where the gate down the main road will be closed. Park here (make sure to display your Adventure Pass). The rest of the approach continues on foot.
Here's how to get from your parked car to the rappel wall.
Walk past the gate and follow the main road about 1 mile to the Horse Flats Campground entrance, which will be located on your left. Go through the locked gate and walk to the back of the campground to Campsite #9, where you will see a small trail leading to a prominent boulder garden up the hill and to the right. Continue on the trail until you reach the main bouldering area (about 5-10 minutes walk) and look for the rappel lines set up on a big rock that resembles a small version of Half Dome, about 50 yards off to the left. Keep an eye out for hot pink ribbon markers that will help lead you from the trail to the wall.
Keep in mind the walk to the climbing area is about 2.5 miles, most of it on roads and well-developed trails, so you will enjoy a small hike in addition to all the vertical activities.
You could easily ride a bike from the parked cars to the campsites, as the first 2 miles of the approach are paved. If you bring a mountain bike you could ride it all the way to the main boulder area, but would have to stash it somewhere out of the way or carry it to the rappel wall.
If you want to be on the rock at 10 a.m. sharp, it's recommended you leave Los Angeles by 7:30 a.m. to give time for both the drive and the walk in. It's OK to not be on the rock at 10 a.m. sharp.
If you are interested in camping at Horse Flats the night before the workshop, a group of us, including the organizers, will be doing so and you are welcome to join.
Print this webpage and bring it with you, as mobile phone reception becomes unreliable in the mountains.
On the day of the workshop, we will do hands-on learning of knots and rappel technique. These visuals cover some key topics. Look them over and make this page handy as a reference. Don't worry if things look confusing or hard to remember. Once you get your hands on the rope and webbing, you'll learn quickly!
Standard method for closing loop on webbing.
Source: Basic Rockcraft (1985). Robbins, p. 20.
Important climbing knot.
Source: Knots for Climbers (1993). Luebben, p. 8.
Classic/improvised/emergency harnessing system
Source: Mountaineering: Freedom of the Hills (2003). Cox, p. 196.
Source: Advanced Rockcraft (1985). Robbins, p. 63.
Classic/improvised/emergency descent method
Source: Mountaineering: Freedom of the Hills (2003). Cox, p. 198.
Download, print, and bring these resources: