A climb with some fun and burly moves, but some detractors. It seems that the mineral being secreted here is in fact guano. I've certainly climbed worse, but if you are averse to bats or poo, you should avoid this climb.
Start up into the shallow, left-facing corner just left of the white-washed arete. Fight up and into jams and place some gear. The crux comes low on this line and is protected by hand-to-fist sized gear. The jams are sharp and spots of the climb are dirty. About the time the corner ends the rock gets less steep and the climbing eases... there are bats in the line back there, and while noisy, they did not otherwise effect the climb themselves.
The line by Gillett proceeds up, then up and left through some lichenous-looking rock with seams and cracks for a little over 100', about 5.9- according to Gillett, where one can scramble down to the East to some anchors and rap. We opted to finish up and right to the anchor on Will Chevy Slab to the rap and head down the 85' rap to the ground.
This route is toward the left side of the right half (S-facing) or Observatory Rock. The beginning is approached from the right, coming out onto a ledge below the left side of a large flake, where a white-stained arete lies on the right side of the crack. This is the start of Mineral Secretion.
Just right of this is an obvious fist-crack splitter that starts well off the ground and continues for 20'... the start of the route called "99% Pure."
This route will take a rack up to LARGE cams, but can be safely lead on a rack from small to a #3 Camalot. A #4 will put gear higher at the crux, and with LARGE cams you might essentially TR the bottom crack.
From: Pinewood Springs
Mar 21, 2014
One can start 20' lower in a licken corner for additional moves that lead to the crack on the left of the alcove. The crux comes at the horizontal where there is a hidden sidepull. A #4 Camalot was useful at the top to protect the move around the roof. I had to take my helmet off to do the move.
The guidebook shows a pic for this climbing area and a dotted line for this route that is on the right side of the alcove; however, in the topo, the line for this route is on the left side. To add more confusion, the 10b variation is the thin flake in the middle.