Climb the finger crack crux off the ground. This is 5.9 to 5.10+ depending on finger size and reach. Being taller with fat fingers helps. You can get finger size cams, but don't fall, because without a perfect belay you'll land awkwardly on jagged rocks.. DON'T SMEAR ON THE PETROGLYPH! Easy 5.4 stemming leads to the top.
Ethics Rant
I recommend people avoid this climb, because (1) it's a moderately painful 10' boulder problem followed by much easier non-descript climbing so it's boring for a 5.10 climber; and (2) if you're not a 5.10 climber, if you don't take a short ankle-twisting fall on the sharp rocks, you'll probably leave shoe rubber on the rock art- which is exactly the type of behavior that gets entire areas closed because non-climbers/land managers (in this case- LA National Lab) just don't understand how important it is to climb every crack there is. (That being said- the LA Mountaineers unofficial toprope group always seems to have a rope set on it when they visit the Y and that organization has been climbing here longer than anyone else...)
Location
Just to the right of the cave on the north side of the 'Y', right of Wisconsin and the Nose, find a finger crack right next to a petroglyph.
Protection
1 set nuts, 1 set cams to 1". 2-bolt anchor, reachable from the top, was installed by unknown parties to prevent further damage to trees... which pisses me off because it will encourage traffic and possibly lead to damage to the rock art.