A beautiful and aptly-named formation with a few good routes on high quality rock.
The summit is excellent (and don't believe the old guidebook...there's no 4th class or easier route to the summit).
From the town of Johnsondale (near the M99/M50 junction, 24 miles North of Kernville), take the lower Kern River Road north (aka 22S82). 2.6 miles down Lower Kern River Road on the right hand side, is a gate at the entrance to Camp Whitsett Boy Scout Camp. The well-traveled path up to Sentinel begins across the road, approximately 50 yards down the road past the camp entrance. The trail begins near the second pedestrian sign (the one that faces east--you'll be looking at the back of the sign as you drive up).
The trail is generally well traveled and easy to follow. Half-way up the ridge, you will come across a large rocky outcrop. Scramble up and right from the point where the tail meets the outcrop. Scramble up over slabs (class 2-3 with moderate exposure) until you regain the hiking trail on the back side.
In all, the hike covers 1,400 feet of elevation gain over 1.5 miles of trail. When you reach the summit block, the easiest way up is a short 5.4 pitch up the exposed northwest corner of the block (only 20 feet of climbing, but the landing is bad). This pitch can be lead with a single medium TCU and a 2-inch piece. Belay (and rappel) from bolts on top.
The route starts below two parallel cracks near the base of the south buttress. Face climbing past 2 bolts leads to the right-hand crack. Crack climbing leads to a ledge. A short pitch up a left-facing dihedral leads to another ledge. The crux pitch climbs vertical knobs past 2 bolts. Belay on a spacious ledge with a massive block. Scramble back away from the edge and up until reaching the steep summit headwall. Climb a clean crack to the summit....[more]Browse More Classics in CA
Hey, I work at said summer camp and have led morning hikes up to the top for two years now. If you do decide to go up during the summer, i would suggest going in the morning when its cool, as it gets quite hot and a lot of the trail is loose sand towards the top. (plus you get to see the sunrise if you go early enough) its also pretty easy to get lost on the way down, so keep a look out for the trail markers.
Regarding the "start" of the trail. The trail from the scout camp crosses the Lloyd Meadow Road where the pedestrian sign is - this is about 1/4 mile east of the Camp entrance. There is a little turnout there to park. The trail is in the water course for maybe 30 feet then cuts out right.
On the way up there is a rocky place about halfway up, cut up right on the very clean white rock with pleasant scrambling to stay on the main "trail". Going left you will do some interesting scrambling before regaining the trail.
The top area is a wild windy place, like being at the Needles. After sweating up the sand slope I was cold in the wind! The view is tremendous. I didn't climb to the very top but it looks to be easy fifth. I'd think coming down would be scarier than going up. A short rope and a few nuts/cams should allow safe up and down lead.