Crystal Lake to Mount Islip, June 21, 2025

Led by Gail Wise and Heidi Lennartz

By Heidi Lennartz

Greetings Hikers: Eight nature-loving hikers met on this bright sunny morning above the Valley clouds at Crystal Lake (5,539′) above Azusa to hike up to Mount Islip (8,250′), one of the beautiful ‘Hundred Peaks’ in Angeles National Forest, elevation 8,250 feet.

We met at the convenient Sierra Club-designated Ride Share Point in Azusa and carpooled to the trailhead. What was a drizzly morning in the basin turned into a cool, sunny day at the trailhead with the mountain towering before us.

GLS hikers on the trail. Photo Nancy Beverly.

After our trail prep, we headed up what was mostly shaded single track trail, through lovely oak trees, wildflowers, sages and a steady 12 degree incline almost the entire way. It was 2.5 miles up to Windy Gap, then another 0.8 miles to Mount Islip peak, a former fire-lookout station. The remnants of the original stone hut is still there, along with a simple painted tile for the peak marker.

A tile on the register can at the summit of Mt. Islip. Photo Heidi Lennartz.

We enjoyed our lunch and snacks with spectacular views of the Antelope Valley, Mount Wilson, Baden-Powell, and the Hawkinses, but the clouds in the San Gabriels and L.A. basin persisted, so no southern views except for the tall peaks in the distance looking like floating islands.

After lunch, we doubled back for half a mile to the Big Cienega Canyon turnoff and a 4.0 miles descent down the ridge, then along the canyon wall back to Crystal Lake. During the descent, we came upon a set of car keys in the middle of the trail! Luckily, we had just passed a young man heading up and with the power of Nancy’s vocals, we summoned him back to get his keys! Lucky guy.

All in all, we completed the hike in 4.35 hours and traveled 7.7 miles without incident! Thanks go to Gail Wise for planning this beautiful day and Heidi Lennartz for sweeping.

Clouds over Los Angeles on the hike up. That’s Smith Mountain just poking up through the clouds. Photo Heidi Lennartz.
Paintbrush and golden yarrow by the trail. Photo Nancy Beverly.
Penstemon by the trail. Photo Nancy Beverly.
Yucca in full bloom by the trail, with Nancy for scale. Photo Nancy Beverly.
On the Islip Ridge Trail, heading down from the peak to the Big Cienega Trail. Twin Peaks is in the distance, and Mt. Wilson beyond. Photo Heidi Lennartz.
Trail sign at Windy Gap. The Vincent Gap Trailhead, 9.4 miles to the east, is the start of the climb to Mt. Baden-Powell. It’s also where the San Andreas Fault crosses the ridgeline of the San Gabriels. Photo Heidi Lennartz.