One of the trad testpieces from the late 70s, GI is located on the left side of Bell, just right of the tree at the start of Hound Dog. From a right hand jam (or lay away) and right foot cam, clip the bolt and power up to a sloping finger bucket, match, and throw for the jug. Climbers under 18 are allowed to just campus this, but the rest of us can make use of some small smears to set up the throw. Make strenuous moves up and find tricky gear (stoppers, small TCU), then step left around the corner on finger crimps, move up s few feet, then back right and into a crack formed by the right side of a pillar. This is the original line; it is possible to climb straight up from the gear, over a difficult bulge, to get to this point directly (harder, powerful and pumpy- this is how The Purpose i.e. "Chop Your Dieckhoff" was accessed when led on gear). Follow the crack to its top, clip a bolt, then climb 10 or so feet of thin 5.10 to where the climbing eases (scary). Clip the rap anchors after you de-pump. An excellent pitch of climbing.
Protection
Bring a set of RPs & wireds nuts, TCUs or Aliens, up to a 3" cam (you could use a 3.5" cam in the crack behind the pillar before clipping the 2nd bolt). Note the crux is well protected by a "newer" bolt that resides next to the original quarter incher (which was placed using a ladder!). There is a little bit of a runout moving left around the corner after the crux. The "s" rating is for the 15 foot 5.10 runout at the top, after the 2nd bolt.
There is a right kneelock right after the dyno on GI that really helps, esp. for getting that gear in. I just did the "direct" again recently, going straight up instead of L around the corner, and it felt like 12a climbing. The "trad" Purpose is actually accessed from immediately after the crux dyno at the start (i.e. just below the bulge on GI), and moved right roughly at the level of the crystal seam to the bottom of the vertical "fin".
I replaced the hanger on the 3/8" stud (bolt that protects the opening dyno)--please don't take it. Would be great if someone took the time to pull the old buttonhead. --josh wharton