Thin moves down low lead past the crux and to a thin corner. Climb this corner aiming for the larger corner system. Follow up and to the right to the Gemini Rappel anchors. A double rope rappel puts you back on Sentry Box Ledge.
Location
First Return is the left most route of the three routes (Gemini Crack and Zodiac) located on Sentry Box Ledge.
Protection
Standard NC rack with some small gear (aliens, nuts), long runners, double ropes. Rap anchors at top.
This climb starts on sentry box ledge at the far North end. Climb the face (5.8) to inside corner, or start in corner itself. this crack ends at a kind of slabby overhang. Pull to Left (supposedly a hidden jug) or right to nice gear belay 120 ft(5.8). 2nd pitch follows crack to the top 180 FT (5.5). There are a nice new set of Rap bolts about 20 ft North of the big tree. Previously the tree was the rap anchor. Now the rap does not interfere with the other routes that come up from the ledge.
I don't think those distances, mentioned in the above comment, are correct (p1 = 120 ft + p 2 = 180 ft = 300 ft). The two pitches can be combined into one pitch that is less than 200 ft pitch. And the rappel from the new bolts is approximately 180 ft to Sentry Box Ledge. I will find the pdf of the new anchors and post...it is attached to the Gemini Cracks page.