The East Face of The Thin Wall is a top-roper's dream come true. There is something for everyone here - from 5.6 to 5.11a. There are a handful of bolts up top (Congratulations and Count On Your Fingers / No Calculators Allowed), and where there aren't bolts, gear is required. If toproping, a short static rope or some long webbing is especially helpful.
The downside of Thin Wall is that on any given day, there are about a million people here which creates a bit of a circus-like atmosphere. Thin Wall is popular with the Boy Scouts, church groups, and every other institutional group you could imagine.
The difficulty of the routes tends to generally increase as one moves left along the face.
Nearly all of the routes can be led safely, except for Child's Play (5.10d) and Congratulations (5.11a) - the two leftmost routes. Although it doesn't receive an "R" rating in Vogel's guide, I have personally stayed away from leading The Face of Tammy Faye (5.8), as pro looks sparse.
Descent: scramble to the north or south (4th class), or rap off fixed anchors for No Calculators Allowed
Getting There
From Real Hidden Valley parking area, follow nature trail north to "T" intersection. Head left (NW) on trail. The Thin Wall is the prominent rock "fin" on your right.
The Classics
Mountain Project's determination of some of the classic, most popular, highest rated routes for The Thin Wall:
Maybe I was more dialed in at this crag then I was at others, but in my honest opinion, the ratings at this crag were more merciful. I found 5.10+/11- to be at the limit of my ability at most J-tree crags, but not so hard here.
The West face has a route called "Sandbag" that is a very technical lead. One should be a solid 10c leader. Remember to double back your harness. The one time I forgot to was when I led this route. Thank God I didn't fall!
By 5.10b4me From: Alhambra, California Apr 8, 2003
I agree with Tony. I thought that the route ratings were more in line with other crags in the country. in other words, I thought these routes were overrated for Josh.
re: crux at top. That's so typical of Josh. the crack gets wide at the top and a little groveling is involved. It's not just the Thin Wall. Done many a route here and cruse'd the crux only to feel like a beached fish at the top.
Just a comment on how the area has changed over the past few years. This area used to be a ghost town since it was primarily a top roping crag and I guess must have lacked a certain cache. I mean you could have shot a cannon at its base and only graze a few plants. Gladly, it's nice to see that its popularity hasn't resulted in a proliferation of bolts.