Page Type Page Type: Mountain/Rock
Location Lat/Lon: 34.34500°N / 117.839°W
Activities Activities: Hiking
Seasons Season: Spring, Summer, Fall, Winter
Additional Information Elevation: 8250 ft / 2515 m
Sign the Climber's Log


Windy Gap
At Windy Gap; the Mt Islip trail is immediately behind Travis climbing right.

Mt Islip, one of the more popular peaks in the northeast San Gabriels, stands along with its sister peak, Mt Wiliamson astride Islip Saddle. Named after George Islip, the peak is relatively separated from its neighboring peaks providing stunning views on clear days in all directions. A cabin in ruin just off the summit attests to its importance in bygone years as a fire lookout.

According to the Angeles National Forest website, “One of the earliest two-way radios used by the Forest Service was located at this lookout for fire reporting during the 1930's. Forty years ago, there were many more lookouts on various peaks of the Angeles National Forest, but the increase in smog decreased visibility so much that their effectiveness was greatly reduced, and they were closed.” More history on Islip is available in John W. Robinson’s excellent book Trails of the Angeles.

Getting There

Mt Islip can be approached from three different directions: Angeles Crest Highway (SR2) from La Canada, Angeles Crest Highway (SR2) from Wrightwood, and the San Gabriel Canyon Road (SR39) from Azusa. The Angeles Crest Highway from the south offers access to the quickest and most popular routes to the summit as it allows the hiker the ability to park at Islip Saddle, in the shadow of the Mt Islip. Current road conditions for SR 2 and SR 39 can be found at the Caltrans website.

    • To get to Islip Saddle, take the Angeles Crest Highway from La Canada (SR2 off-ramp on the 210 Freeway) north for 39.5 miles. A junction with the Angeles Forest Highway is reached after 9.5 miles – stay right to continue to the saddle. This is a very popular route on the weekends with motorcycle clubs, auto clubs, and bicyclists -- park in the paved parking lot at the saddle next to the locked gate.
    • The Angeles Crest Highway from the north is reached by taking Interstate 15 north and exiting off the 138 West just before ascending the final grade of the Cajon Pass. The junction with the Angeles Crest Highway to Wrightwood is reached shortly. Wrightwood can also be reached from Palmdale using the 138 East. Shortly after passing through Wrightwood, the Angeles Crest Highway (in the village of Big Pines) turns southwest until it terminates at the Vincent Gap parking lot (about 5 miles). Like the Islip Saddle, a locked gate as of this writing prevents further travel on SR2
  • Highway 39 is reached by taking the Azusa Blvd exit north of the 210 Freeway. After 12 miles, a junction with the East Fork of the San Gabriel River is reached. Continue past this junction and continue to head north until a gate blocks further progress. Park and walk the remainder of the road up to one of two trailheads.



There are several trails and routes that can be used to approach or hike Mt Islip. For specific details, see the route pages attached to this mountain page.

Windy Gap: The Mt Islip trail, maintained, leaves Windy Gap and climbs to the top of the peak in a little less than a mile. An alternative from Windy Gap is to climb the east ridge (steep use trail) up to the summit or to where the Mt Islip trail crosses the ridge north to south. A side trail can also be used to reach the Mt Islip trail from Little Jimmy Campground. There are multiple ways to reach Windy Gap.

    • From Islip Saddle, take the PCT until you get to Windy Gap (2.4 miles). You’ll hit Little Jimmy Campground first (2.1 miles) providing an early opportunity to get on the Mt Islip Trail.
    • From Islip Saddle, walk the closed Angeles Crest Highway north until you reach highway marker 66.37. Climb up the gully (about a ¼ mile) – you should find a use trail. This route takes you directly to Windy Gap. More detailed information is found on the Sierra Club’s HPS List.
    • From the Vincent Gap parking lot, you can choose to either hike the road (about 9.5 miles) to highway marker 66.37 (mentioned in previous description) or hike up the Baden Powell trail to the PCT and follow the ridgeline (past Baden Powell, Burnham, Throop, and Hawkins peaks) to Windy Gap (about 9 miles).
  • From the locked gate at the end of SR39, follow the road and (short-cut) trails up to the Crystal Lake Campground and the day use parking lot (about 5 miles using the shortest route). The trail is signed for Windy Gap (2.5 miles).

Northwest Ridge: The ridge branches near the bottom and either branch can be climbed. The NW branch begins shortly into the hike on the PCT from Islip Saddle while the N branch is about 8/10 of a mile into the hike. Follow the ridge (~1.25 miles).

Islip s SW ridge
Islip's southwest ridge with Crystal Lake below

Southwest Ridge: Two possible routes from the Crystal Lake area gain entry onto the southwest ridge of Islip. Once on the ridge, the unmaintained trail meets the Mt Islip trail just before the final switchback up the summit. Expect numerous fallen trees to be blocking the trail.

    • The Windy Gap route leaves the Crystal Lake Campground parking lot (see fourth description under Windy Gap) and meets the Big Cienega trail just after crossing forest road 3N07 (at 1.1 miles) for the second time. The Big Cienega trail then climbs west to the ridge (1.8 miles) and heads up to the junction with the Mt Islip trail (0.9 miles).
  • Instead of heading to the Campground, go to Crystal Lake (about the same distance). At the south end of the lake, take the Crystal Lake trail up and north on the ridge where it meets the Big Cienega trail junction (3.9 miles). Continue up the ridge until the trail meets the Mt Islip trail just before the summit (0.9 miles). This trail is also called Islip Wawona trail on some maps.


Red Tape, Camping, and Conditions

Islip Junction
The junction just before the summit with the Mt Islip trail and the Big Cienega Trail

You will need an Adventure Pass or Golden Eagle Pass to park your vehicle at any of the three parking areas. Besides some Forest Service locations, they are sold at most major sporting goods stores in southern California ($5 per day and $30 for an annual pass). Up to date information on conditions can be obtained from the Angeles Forest website.

Little Jimmy Campground is the closest campground to Mt Islip but there are many in the San Gabriel Mountains. The mountain can be hiked in almost any season but May through October are the most popular times. In heavy snow years, the PCT trail (on the north facing slope) can be covered in snow and additional cold weather gear (snowshoes, crampons, ice ax) may be required. Check for current weather.

See Steve Larson's excellent webpage for more information on the San Gabriel Mountains.


External Links

Trip Reports/maps:

Bob Burd's trip report


Rick Kent's pics

San Gabriel Mountains Discussion Board

Additions and CorrectionsPost an Addition or Correction

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T. White

T. White - Sep 21, 2022 4:46 pm - Hasn't voted


Be warned - there's been a rash of car break-ins at the Islip Saddle parking lot. Leave your doors unlocked - even items of no value are being stolen.

Viewing: 1-1 of 1



Children refers to the set of objects that logically fall under a given object. For example, the Aconcagua mountain page is a child of the 'Aconcagua Group' and the 'Seven Summits.' The Aconcagua mountain itself has many routes, photos, and trip reports as children.