An excellent offwidth route up an aesthetic tower! Start on the downhill face, up the obvious offwidth in a left-facing dihedral which pierces the entire tower and separates the main pinnacle from the flying buttress to the left. There's a plaque beneath the route, and a summit register wedged into the loose summit blocks.
The name comes from the profile of the tower, which is thumb-like from most directions, but especially so when viewed from directly downhill with the flying buttress as the fist and the summit pinnacle as the thumb.
P1- Starts out with new #5 camalots and gradually widens to sustained squeeze (wider than tipped out #6 friend) by the top. The rock is great, with just a bit of sandy stuff as you pull over onto the belay ledge. There are two bulges, the lower being the crux and is conveniently laybacked around. A really nice pitch, even for those who aren't OW gurus. Good belay ledge. 5.11 90'
P2- A 6 bolt ladder to the three bolt summit anchor, which is a bit below the actual summit due to rock quality. The bolts are well-spaced, so aiders are nice to have. The true topout requires carefully scrambling atop some loose blocks, a bit unnerving at first glance, but we successfully perched four guys up there without mishap. A0 25'
The tower is found in the back recesses of the canyon between Critics Choice and the Prow. It's not really a part of Critics Choice, but that's the closest area.
Drive 4.8 miles up Beef Basin road from the junction with 211 (at the toilet) and turn right on a two-track. Follow this for about 1/2 mile (passable for most vehicles) until it deteriorates into a wash. Hike up the road for another 1/2 mile or so and then cut over to the hillside following washes. Slog uphill in a defined wash that has some shitrock hoodoos on the left. This should put you beneath the Thumb after about 45 minutes to an hour.
The tower is hidden against the adjacent cliff, and is very hard to discern until you're up beneath it on the approach. The route lies on the downhill face of the tower and ascends the splitter OW in a left-facing corner with a plaque beneath it.
1-new #5 camalot, 2-new #6 camalots, 2-#6 friends, blue big bro, aiders, jumars.