From the parking lot follow the gravel road past the gate. Take a left at the first obvious point, and continue on this trail, skirting the river. If you get to a point where the river cuts right and there's a small metal fishing platform you've gone too far. Trace back about 100 feet and find a path the climbs into the forest. Follow the path a couple hundred feet to the base of the cliff. Here the track forks to the right and left. A short walk to the right will take you to the lower end of the Galaxy Wall.