© Christopher Earls Brennen

Hike D15. East Fork of Santa Anita Canyon


One of the prettiest, untravelled canyons in the front range of the San Gabriels is the East Fork of Santa Anita. Though the bottom end is easily accessed from the popular and well-travelled trail from Chantry Flats to Sturtevant Falls, few hikers venture up the East Fork. This adventure hike begins at Chantry Flats, drops down into the main canyon via the established trails and then climbs a steep ridge up the east wall to access the remote Upper Clamshell dirt road. It then travels north on the Upper Clamshell to a point where you can drop down into the East Fork of the Santa Anita. You then descend the East Fork, a hike that involves much bouldering and one substantial rappel down a vertical 70ft waterfall.

This hike is probably best in the winter or spring when the climb up the ridge is not too hot. On the other hand there are many marvellous swimming holes in the East Fork that would be great in the summer. One drawback to this hike is the large quantity of poison oak in the East Fork; protection is recommended for those who may be sensitive.


Drive north on Santa Anita Avenue in Arcadia, continue up the mountain road to Chantry Flats (34o11.77'N 118o1.35'W and elevation 2100ft) and park there.


Beginning in the Chantry Flats parking lot (34o11.77'N 118o1.35'W and elevation 2100ft), follow the asphalt road descending into the canyon. After about 150yds take the trail leaving the right side of the road and follow this down to the Santa Anita river. Crossing to the east side, continue downstream, following the canyon bottom trail to Hermit Falls (34o11.49'N 118o1.05'W and elevation 1460ft) which you should reach about 35min and 0.9mi from the start. Take a moment to explore and admire these lovely pools and waterfalls.

East Fork Waterfall   Pool in lower canyon

To proceed, climb the steep slope to the right of the falls area in order to access the trail that continues downstream. After just a short distance, you should fork left at the first house you encounter. Descend beside the house to a stream crossing. On the other, eastern side of the canyon bottom, locate a broad flat bench, the starting point for a steep climb up a ridge on the eastern wall of the main canyon (34o11.36'N 118o1.09'W and elevation 1420ft). Start up the steep, wooded but open slope to the left of the bench. Head straight up following the animal switchbacks and veering slightly to the right to approach the apex of the ridge. After several hundred feet you should be able to locate the apex of the ridge that you will roughly follow for the next couple of hours. In places you will be able to find a valuable use-trail that follows either the apex of the ridge or a line a little to the left of the apex (almost never to the right of the apex where the south-facing vegetation is less negotiable). In other places the trail disappears and some serious bushwhacking is required. Near the top there is a grassy area where deer graze and sleep; follow the readily negotiated grass slopes as far as possible. After a final bushwhack, another grassy slope will quite abruptly bring you to the dirt road known as the Upper Clamshell Road at 34o11.39'N 118o0.49'W and an elevation of 2940ft. You should reach this point about 3hr (and only 1.8mi) from the start.

After the tough steep climb (and bushwhack) up the ridge, it is a relief to turn left and hike north along the Upper Clamshell. This is a very rarely travelled dirt road that branches off from the Rincon/Red Box road at an elevation of 4720ft (where it is gated to prevent vehicular access) and descends for about six miles to a valley overlook at 2900ft where there is a watertank but little else. Perhaps the original intention was to build a road down to Arcadia but this never happened.

The road is in remarkably good condition considering how rarely it is travelled. The surface is smooth and I only noticed one place where fallen rocks would prevent vehicle passage. The gradient is also quite gradual. Coupled with the pleasant wooded surroundings, this makes for a most enjoyable hike. The road makes two large incursions into the hillside to contour around the head of two canyons and then rounds a headland with a great view of various forks of the Santa Anita. You then cross above a saddle some distance below the road to enter the East Fork of the Santa Anita, high on that canyon's south wall. Just beyond that saddle, it is important to identify a place where the road turns sharply east. That identification is made easier by the fact that just around the corner you enter a "tunnel" of woods on the heavily forested north-facing slope. The drop-in point for the descent into the East Fork is just 30yds beyond the corner at 34o12.31'N 118o0.22'W and an elevation of 3800ft. It is currently marked by a duck beside a metal water chute on the left side of the road. If you miss this waypoint you will pass a much larger concrete water chute several hundreds of yards further on. Do not descend the gully with the concrete chute but return to the less conspicous metal chute. You should reach the drop-in point about 4hr after leaving Chantry Flats. It is 2.2mi from the point where you accessed the road and 4mi from the start.

Leaving the road, the cross-country route lies down the steep but leafy and open slope in the forest. If you head straight down you will soon drop into a shallow gully that develops into a small canyon that eventually meets the East Fork. The descent takes just 40min and you reach the stream in the East Fork of the Santa Anita at 34o12.64'N 118o0.09'W and and elevation of 2820ft. Here the canyon is quite wide and heavily forested. As you start downstream, there is a broad bench on the south (left) side that makes for easy travelling. However about 0.3mi downstream, the canyon narrows, hard white rock appears and the canyon becomes much more rugged. This culminates in a 70ft waterfall that falls vertically into a deep and dramatic chasm that appears even deeper when viewed from above. Another waterfall a short distance away to the right also drops into this same chasm. It is an awesome place and the highlight of this adventure. You should reach this point (elevation 2570ft) roughly 5hr 20min from the start having travelled about 4.8mi.

There are three possible ways to descend into the chasm. Two involve rappelling about 70ft down the falls using as anchors trees that are a short way back from the lip. One tree some distance back leads to rappel down the falls and will usually result in a wet descent. Another tree off to the right that requires a contour across a steep earthen slope (a belay is advisable here) will lead to a rappel down a dry chute to the right of the main stream. In either case you must wade through a knee deep pool at the base of the waterfall. A third possibility is to climb around the falls by retreating a short way upstream to where you can climb the left (south) bank onto a shoulder above the falls and the chasm. A faint use-trail will lead to a place where a short rappel will allow you to descend to the top of a scree/dirt slope in a steep draw and thence into the bottom of the chasm. Whichever descent route you choose, take a moment to enjoy the surroundings from the bottom of the chasm. In the spring, with both waterfalls flowing freely it is a beautiful spot.

Downstream of the chasm there are many smaller waterfalls and lots of lovely, deep pools. The going is slow since you must find your way around and down through these many obstacles. But none require technical equipment. The descent through this lovely stretch of canyon takes about 1.5hr. You should reach the end of the East Fork about 7.5hr after the start having travelled about 5.6mi. Here the East Fork meets the main Santa Anita canyon and you access the popular and well-travelled dirt road from Chantry Flats to Sturtevant Falls at 34o12.78'N 118o1.04'W and an elevation of 1940ft.

From here it only remains to hike that popular trail down the main canyon and then up the asphalt road back to Chantry Flats. The total hiking time should be about 8hr in which you cover about 6.9mi.

Last updated 4/25/01.
Christopher E. Brennen