Sentinel Rock YVF
Sentinel Dome YVF
Illilouette Ridge P900
Peak 8,142ft
Ostrander Rocks
Taft Point YVF

Mon, May 20, 2013
Sentinel Rock
Sentinel Dome
Story Photos / Slideshow Map GPX Profile

Sentinel Rock

Sentinel Rock is one of the defining features of Yosemite Valley. It looms high on the south side of the canyon to the west of Glacier Point, prominently seen from the Yosemite Lodge environs. Its imposing North Face was first climbed by John Salathe and Allen Steck in 1950 in what was the hardest rock climb done in America at that time and has continued to be considered a classic up to the present despite a difficult approach. Fortunately for me there are easier routes though I didn't have much information about it. Had I read Roper's guide (of which I have several copies, so no excuse there) I would have found there is a class 3 route starting from partway up the Four Mile Trail that leads to a notch on the south side of Sentinel Rock and from there to the summit. No, this one I left to my own observations over the years, eventually being taken more seriously when I was climbing Lower Brother with Adam the previous week. During our adventure on the north side of the canyon, I spotted what looked like a climbers' trail traversing west from halfway up the Four Mile Trail. I guessed that the trail was so prominent because it must be the descent route from the top of Sentinel Rock which I knew to be a fairly popular rock climb for many decades. I made a mental note of the trail and even took a zoom photo of it for future study, but it was only a week later that I decided to come back and pay it a visit. It turned out the trail I spotted and subsequently used had nothing to do with climbers and Sentinel Rock, but I made it work anyway.

It was after 11p when I pulled up to the entrance station on SR120 leading into the park. I slept 4-5 hours at my recently discovered TH near Foresta just outside the Valley itself, and was starting up the Four Mile Trail by 6:40a the next morning. Sentinel Rock is plainly visible from the start though the impressive North Face was steeped in shadow as the first morning rays were lighting up its SE aspect. I was happy to enjoy the shade on a cool morning, climbing some 2,400ft over four miles in an hour and a half. Given the name of the trail you'd think I should be at its end, but the dirty little secret is that the Four Mile Trail is really closer to six miles than to four. Many years ago they added additional switchbacks to make it easier for stock, not bothering to change the name which by then had been entrenched in Yosemite lore. All the while during the hike I took in the swell views of Yosemite Valley afforded by the trail, also studying portions of the north side of the Valley for possible future scrambling routes back on that side (in particular, I liked the look of a route going up from the Yosemite Falls Trail between Columbia Rock and Eagle Tower). I took a short detour to visit Union Point just off the trail, sharing the view with a few lizards that scurried about the rocks. In addition to a good view of El Cap, there is a helpful view of the east side of Sentinel Rock and the steep chute on that side I would use for the ascent.

The exit I was looking for off the trail is only a short distance past Union Point. I found a first use trail leading steeply down from the main trail which I followed for perhaps 100yds before deciding it wasn't what I was looking for. I returned to the Four Mile Trail and found the old trail I had spied from across the Valley not much further up the trail. The turnoff is not obvious and there was some minor thrashing through the brush before I stumbled upon what turned out to be more than a use trail. In fact it had been maintained at one time, a decent trail cut in the hillside running south across the steep slope. It did not take long to realize this trail had been cut to service a pump station located a few hundred yards along it, an interesting story in itself.

If one looks at a map of the Yosemite Wilderness, you will see an odd, non-wilderness corridor that runs up the drainage east of Sentinel Rock from the Valley floor to Glacier Point. Power lines run up this drainage to supply electric power to Glacier Point where a Visitor Center can be found and at one time, a hotel was located. I'm not sure if the Park Service has since run power from Badger Pass to Glacier Point buried underneath or alongside the Glacier Point road, but the power lines running up past Sentinel Rock appear to be intact and in good working order. Halfway up the drainage is located a stone structure along the old trail I was on. Inside is an old pumping station with a steel water tank located just outside. Pipes ran further south to the year-round creek that flows down the drainage, bringing water to the station where it was then pumped back uphill to Glacier Point, supplying that location with water. The pump has not been in service for many decades, from the looks of it, possibly not since the hotel burned down in 1969.

Once I realized my trail had nothing to do with climbers going to or from Sentinel Rock, I went about figuring a way to make it so. The primary trouble was that I was more than 600ft too high and would have to scramble down this distance to the base of the chute on Sentinel's east side before beginning the climb back up. From below it had looked like the old trail would traverse around to the formation, but I could now see that intervening cliffs made this impossible. Two thirds of the descent proved relatively easy, class 2-3 terrain running under the utility lines without much bushwhacking involved. There was an old nylon rope running down much of the slope, perhaps used by service technicians at one time to facilitate reaching some of the more remote poles in the drainage. The rope has been out of service itself for a long time, cut many times by rockfall, buried in places, and not really necessary anyway as the slope isn't very difficult. As I got closer to the creek, the brush increased and the bushwhacking took on a more serious flavor. Still, it wasn't too bad overall, taking about 40 minutes to get from the old trail down to the start of the chute which is found shortly after crossing the creek in the middle of the drainage.

The drainage/chute running up the east side of Sentinel splits into two branches about halfway up. The correct branch to reach Sentinel Rock is to the right, the more obvious main branch. The lower portion of the chute, before the split, is a loose pile of class 2 talus and boulders. After the split, the scrambling is more difficult, but really never more than class 3. It took about half an hour to climb just over 1,000ft up the chute. It was after 9:30a when I reached the notch at the top of the chute. The west side descent from the notch, which has no mention in the literature looks to drop off in a hurry. I suspect only rappels would work going down that way, but really couldn't tell from my perch. The scramble from the notch to the summit of Sentinel Rock took about 15 minutes, an interesting class 3 affair weaving through manzanita and other brush, over and around large boulders, eventually landing on the short summit ridge. There are a few ducks and one can tell the brush had been clipped in places, but for the most part the route is obvious because almost nothing else will work without a rope. The high point was at the west end of this ridge, but I didn't come to this conclusion until I had first climbed the lower points further east. There is no one place at the summit to take in all the views. The lower eastern points have the best views of Yosemite Falls and the middle section of the Valley around Yosemite Lodge, while the higher western summit has an unmatched view looking down at the west end of Yosemite Valley around El Cap. To the south can be seen Sentinel Dome and the valley rim behind a 400-foot cliff that bars what would otherwise be the obvious route to Sentinel Rock from above. There was no register (I think rock climbers in general disdain these things) that I could find, no cairn or benchmark. The climbers seem to have done a good job of taking all their gear with them and leaving no trash. The only evidence of visits I could find were a few small fire rings just south of the summit on a sloping, sandy platform which has probably seen a few bivies from climbers getting caught out after a late finish.

I scrambled back down to the notch then found a class 4 route up to the lower highpoint found between the notch and the 400-foot cliff face. I vaguely thought this was another feature called "The Nail", mentioned in Roper's guidebook, but I later determined The Nail was another feature, lower and about 100yds further south. Oh well, it was a fun little diversion that involved a neat tunneling manuever to find my way up from the notch. Back in the main gully, I started down, finding what was surely a climber's descent trail that ran down the arete between the two main branches of the drainage. This was a steep staircase-like descent that was better than the chute itself, but ended with a rappel. Huh? Not sure why this had become the preferred route, but I guessed it was probably because most climbers are carrying a rope and a short rappel is rather trivial. I was lucky I was carrying a short rope myself, or I would have had to climb back up 300ft to get back into the main chute. My 30m rope just made it down into the gully from the rap station I had found, and from there I continued down to the bottom, across the bushwacking section over the creek, more bushwhacking and then the easier, clearer route back up to the old trail leading to the stone building. For the record, the shorter way to descend Sentinel Rock is to head down the creek from the bottom of the chute along some improbable ledges and tricky route-finding to about the 1-mile mark of the Four Mile Trail. Maybe another time.

Curious, I decided to check out the stone building and the old pump station. There were some rusty shovels and other tools scattered about the building, but for the most part it had been abandoned long ago and probably sees few visitors. On the other side was the water tank and the path continuing south. An old iron pipe had been replaced with PCV long ago, but that too has fallen into disrepair, broken in several places by rockfall. I followed the path about a quarter mile to its terminus where a small concrete catch basin was built to divert the water from the creek into the pipe. I spent the next 45 minutes scrambling and thrashing my way up the steep drainage, making my way to the Valley rim where it overlooks Sentinel Rock. I thought I would pay a visit to the top of that 400-foot cliff that blocked access from that direction. I got close, but was stopped by a smaller cliff band that blocks easy access to the top of the larger cliff. I could easily have rappeled the short distance past this obstacle, but I wasn't sure I could climb back up it as I had no additional gear to help in ascending the rope. I would leave my exploration of Sentinel at this point. There were other objectives I wanted to visit and turned my attention to them.

Sentinel Dome

Less than a mile to the southeast was Sentinel Dome, a popular destination for visitors to the Glacier Point area with a short trail leading to the summit from the east. I had never been to Sentinel Dome and thought it would be a good time to visit. I approached it from the northwest, looking for a scrambling route as an alternative to the trail. After hiking up the base of the dome on the northwest side for some distance, I found a class 3 friction route leading onto the dome and eventually to the summit from the west. There were several dozen folks found milling about the top. As expected, there is a grand view of the Yosemite high country from the top. One can see Yosemite Falls to the north, Tenaya Canyon and Half Dome to the northeast, Vernal Fall to the east, the Clark Range to the southeast. Atop Sentinel Dome is a large metal disc that points out the names of various summit that can be seen in all directions in the distance with the view etched into the disc with labels - a work of art, really. I descended off the south side of the dome, once again forgoing the trail in favor of the more fun scrambing I found. At the base of the dome I picked up the trail and followed this and a service road out towards the Glacier Point Road.

Illilouette Ridge

Despite its popularity and grand views, Sentinel Dome is not the highest point in the area. About 120ft higher and 1.7 miles to the south lies Illilouette Ridge with almost 1,000ft of prominence. But numbers can be deceiving. Much of the ridge is forested and the views obtained from the top are scant. Further, the summit is large and flat and there's no distinct highpoint to call the top. The cross-country travel leading to the summit is easy, at least, and can be done in a very little time from any of a number of small pullouts along the Glacier Point Rd. Even as I was at the summit my attention was drawn to a series of squat pinnacles to the southwest poking above the forest.

Ostrander Rocks

There are three rocky summits to this feature found about a mile southwest of Illilouette Ridge. The Glacier Point Road runs between them, so it was necessary to return to the road once again and hike a short distance before climbing the steep eastern embankment leading to the summits. The southernmost one that I visited first, easy class 3, turned out to be the highpoint. There were good, unobstructed views from the summit, particularly of the Clark Range to the east. I scrambled along the ridge going over the other two summits in succession, an interesting bit of class 3 fun. The north side of the northernmost summit drops away more dramatically than on other sides, but I was able to keep it at class 3 by shifting some towards the northwest until I reached the easier ground below.

Taft Point

This feature, named for President Howard Taft, is a popular overlook on the south side of the Valley rim, about a mile and a half by trail from Glacier Point Road. My route was cross-country from Ostrander Rocks, about 1.5 miles to the north until I picked up the Pohono Trail and followed it for the last half mile to Taft Point. As overlooks on the south side go, it is surpassed only by Glacier Point. It's a fine spot from which to view El Cap and Cathedral Rocks. It too, is very popular, with about a dozen folks at various points on the wide, rocky top while I was there. On the right side of Taft Point can be found several deep clefts in the rock, only a few feet wide, dropping hundreds of feet to the drainage below. Other than visiting Taft Point for its own sake, my hope was to be able to drop into this narrow drainage, returning to the Valley by this route and possibly climbing Lost Brother on my way down. It was already 4:30p while I was contemplating the possibility of this additional adventure. I had almost 4hrs of daylight remaining which I judged to be more than sufficient (in hindsight, it might have been enough to get me to the Valley floor, but not enough to climb Lost Brother which I did the following day), however, the drainage looked scary. In addition to being steep and narrow, it was wet and grungy-looking, appearing terribly loose and far from what I would consider "reasonably safe." It looked much better on a topo map than it did in reality. I decided against it.

I took the Pohono Trail back to the Four Mile Trail (taking a shortcut northwest of Sentinel Dome that proved more adventure than time-saving) and from there all the way back to the start in the Valley. It was 7p by the time I reached the car, more than 12 hours after starting out, a very full day to be sure. A shower at Curry Village worked wonders to revive my spirits. I ate dinner and watched a movie at the picnic area next to Ahwahnee Meadow, then slept in the van in the Yosemite Lodge parking lot. I chose my spot poorly, too close to the entrance which proved to be a fairly busy thoroughfare for vehicles coming and going late into the night. Though tired, I think my muscles were a little too sore from the day's exertion and I slept poorly. Oh well, I guess that everyday in paradise can't be perfect...


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