Mt Wilson via Chantry Hiking Guide
The Mt Wilson via Chantry route is one of the most rewarding long-distance hikes in the San Gabriel Mountains, climbing from the shaded canyon floor at Chantry Flat to the storied summit at 5,710 feet. The trail threads through second-growth and old-growth forest along Winter Creek and Sturtevant Falls before grinding steadily upward to the historic Mt Wilson Observatory grounds. At roughly 15 miles round-trip with over 4,000 feet of gain, this is a full-day commitment that pays off with sweeping views across the Los Angeles Basin and beyond to the Channel Islands on clear days.
Trailhead Access and Parking
The trailhead sits at Chantry Flat, reached via Santa Anita Avenue north from Arcadia through the community of Altadena into the Angeles National Forest. The parking area fills quickly on weekends, often by 7 a.m., so an early start is essential. A National Forest Adventure Pass or an Interagency Annual Pass is required to display on your vehicle. Overflow parking lines the narrow road, and the Forest Service occasionally restricts vehicle access during fire or storm closures, so check the Angeles National Forest website before you drive up. Restrooms are available at the trailhead.
Route Overview and Key Junctions.
From Chantry Flat, descend the paved road into the canyon and pick up the Gabrielino Trail along Big Santa Anita Creek. After roughly a mile, the spur to Sturtevant Falls branches off — a worthwhile detour of about 0.4 miles to a 50-foot cascade. Back on the main trail, continue upstream to Sturtevant Camp, a historic pack-in cabin area at around 3.5 miles. At camp, the trail transitions to the Mt Wilson Trail, which climbs aggressively through chaparral and Jeffrey pine forest via a series of switchbacks. The final mile delivers you to the Mt Wilson Road and the summit plateau, home to the observatory and several broadcast towers.
Elevation Profile and Physical Demands.
The route is deceptively gentle in its first few miles, descending about 200 feet to the canyon floor before climbing past the falls and Sturtevant Camp. The real work begins after camp, where the trail gains roughly 3,000 feet over approximately 4 miles at grades that occasionally exceed 15 percent. Hikers should expect tired legs well before the summit. The return descent on the same trail is knee-intensive; trekking poles make a significant difference on the way down. Plan on 7 to 9 hours total moving time depending on your pace and how long you linger at the falls or the summit.
What to Expect at the Summit
Mt Wilson's broad summit plateau is unlike most backcountry peaks — it hosts the Mt Wilson Observatory, a Smithsonian-affiliated facility with 100- and 60-inch telescopes that played a central role in 20th-century astronomy. The observatory grounds are generally open to day visitors, and interpretive plaques explain the site's scientific legacy. On clear winter and early spring days, views extend south to the Pacific Ocean, west across the LA Basin, and east toward Mt San Gorgonio. There are picnic tables, a small gift shop during operating hours, and restrooms — a welcome sight after a long climb.
Flora, Fauna, and Seasonal Highlights.
The lower canyon is dense with alder, bigleaf maple, and ferns along the creek, creating a microclimate noticeably cooler than the surrounding chaparral. Spring brings shooting stars and Indian paintbrush in bloom, while fall colors on the maples near Sturtevant Camp are among the best in the San Gabriels — typically peaking in late October to mid-November. Mule deer are frequently spotted in the upper forest, and black bears are present in the range; store food properly and follow Leave No Trace principles. Bird activity along the creek corridor is rich, making this a productive trail for birders.
Safety Considerations
This is a remote, full-day trail where conditions can change quickly. Afternoon thunderstorms are possible in late summer and early fall; turn back if clouds build. Water is available from the creek in the lower canyon but must be filtered or treated — do not drink untreated water. Cell service is unreliable between the trailhead and the summit, so download an offline map in advance. The trail sees rattlesnakes in warmer months, particularly on rocky sections above Sturtevant Camp. Inform someone of your itinerary before departing, carry a charged battery bank, and dress in layers since summit temperatures can be 15 to 20 degrees cooler than the valley floor.
Hiking tips for Mt Wilson via Chantry
- Start no later than 6:30 a.m. on weekends to secure trailhead parking and beat afternoon heat on the exposed upper switchbacks.
- Bring at least 3 liters of water per person; the creek provides a backup source but requires filtration, and there is no reliable water above Sturtevant Camp.
- Trekking poles are strongly recommended — the descent back to Chantry Flat is long and steep and puts heavy strain on knees without them.
- Pack extra layers for the summit; even on warm valley days, wind and shade at 5,710 feet can drop the feels-like temperature significantly.
- If you plan to visit Sturtevant Falls, arrive before late summer when seasonal low flows can reduce it to a trickle — spring after a wet winter offers the best display.
Nearby trails to explore
- Sturtevant Falls Trail
- Mt Zion Loop via Chantry Flat
- Bailey Canyon Trail to Sierra Madre Peak.
Hike this trail with TrailMates
A 15-mile summit hike like Mt Wilson via Chantry is best tackled with people you trust — TrailMates lets you find LA-area hikers matched to your pace and skill level, plan the meetup, and head out as a group with built-in safety features like the 3-person minimum. Download TrailMates from the App Store and find your crew before your next big climb.