- Location: Angeles National Forest back country on Highway 2. From the 210 freeway in La Canada Flintridge, take the Angeles Crest Highway (highway 2) northeast for 40 miles to Islip Saddle, just beyond the two short tunnels. Park in the lot on the left (north) side of the highway. A National Forest Service adventure pass ($5 per day or $30 per year) is required. Click here to purchase.
- Agency: Angeles National Forest/Santa Clara and Mojave Rivers Ranger District
- Distance: 5 miles
- Elevation gain: 1,600 feet
- Suggested time: 3 hours
- Difficulty rating: PG-13 (Elevation gain, steepness, altitude, terrain)
- Best season: April to November
- Dogs: Allowed (exercise caution on warm days; some of the rocky terrain may be difficult for them)
- Cell phone reception: None
- Water: None
- Restrooms: Vault style toilets at the trailhead
- Camping/backpacking: The saddle where the trail leads to the summit (see description) may be a good spot for camping. The summit or Islip Saddle are also options. For information about dispersed/remote camping in the Angeles National Forest, click here.
- Recommended gear: hiking poles; sun hat; sunblock; long pants
- More information: Trip descriptions here, here and here; Summitpost page here; Hundred Peaks page here
- Rating: 10
Updated May 2018
Located on the north slopes of the San Gabriels, Mt. Williamson (elevation 8,214) offers Mt. Baldy-class scenery for considerably less time and effort. With amazing views of the high desert and the lower San Gabriels, Williamson offers a “greatest hits” package of the Angeles National Forest. That said, hikers who decide to visit this summit should be prepared for a challenge. The hike starts at high altitude and ascends rapidly, giving little time to acclimate and the route from the Pacific Crest Trail to the summit climbs very steeply, often over loose terrain, before making a spectacular but unnerving run along a sharp ridge. Acrophobes need not apply.
From Islip Saddle, look for the Pacific Crest Trail, which ascends to the northwest (the South Fork Trail also leaves from Islip Saddle, making its long descent toward the South Fork Campground near the Devil’s Punchbowl). This stretch of the usually moderately graded P.C.T. is unusually steep, gaining 800 feet in the first mile. As you climb, you are rewarded with the first of many views of the high desert as the trail skirts the edge of Big Rock Creek’s south fork. Almost exactly one mile from the start, the trail makes a switchback and heads south, shaded by pines, reaching another switchback in 0.3 mile. Another 0.3 mile brings you to a bench where the Pacific Crest Trail begins to descend. This is a good spot to rest and enjoy some excellent views to the south, notably of the yawning Bear Creek Canyon.
An unmarked but easy to find use trail leaves this spot and heads north, quickly climbing 300 feet over often rocky and loose terrain. At the top of the ridge, you get an outstanding view of the high desert. The trail heads west now, following the ridge in a manner reminiscent of the Devil’s Backbone. While the views from the top are excellent, this stretch is what truly makes the Mt. Williamson hike stand out.
The trail makes a short but sharp drop to a saddle, cutting very close to the edge of the slope an then begins its climb to the summit. A faint use trail on the left brings you to the top (while the main route descends along Pleasant Ridge, eventually meeting Pallett Mountain and Will Thrall Peak). The summit yields a 360-degree view including the high desert, the summits of the San Gabriel middle country (Will Thrall, Twin Peaks and Waterman) and the higher summits to the east, including Throop and Baden-Powell. At the south end of the summit, you can enjoy a particularly dramatic view of Bear Creek Canyon from some precariously balanced granite boulders.
If you were wondering, Mt. Williamson is named for Lt. Robert Stockton Williamson, an Army surveyor, as is Mt. Williamson in the Sierras, California’s second highest mountain.
Text and photography copyright 2018 by David W. Lockeretz, all rights reserved. Information and opinions provided are kept current to the best of the author’s ability. All readers hike at their own risk, and should be aware of the possible dangers of hiking, walking and other outdoor activities. By reading this, you agree not to hold the author or publisher of the content on this web site responsible for any injuries or inconveniences that may result from hiking on this trail. Check the informational links provided for up to date trail condition information.
Are you following me around? Cooper Cyn, Mt Williamson,… But then again, you’ve been to more places than have I. Nice work.
Great minds think alike! Haven’t been to Cooper for a while but I’ll plan on visiting soon. Thanks for reading.
When you hiked Mt. Williamson, did you double back to Angeles Crest? I understand that there is a west loop to Goodykoontz Peak, but that taking this down back to Angeles Crest may take you into restricted frog territory.
Hi Stephan, thanks for reading. Not sure about the restrictions in the area, I’d check with the forest service. Happy hiking.
any update on the frog-inspired restriction on rattlesnake creek trail?
I’m not sure – I found this info that it was lifted at the end of 2009, but sometimes they extend these things longer than expected. https://fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5166692.pdf