Hiking Project Logo

Strenuous climb over pass to Arch Rock, Frog Lake and the beautiful Margaret Lakes.

Your Rating: Rating Rating Rating Rating Rating      Clear Rating
Your Difficulty:
Your Favorites: Add To-Do · Your List
Zoom in to see details
Map Key





Point to Point

10,555' 3,217 m


8,091' 2,466 m


2,758' 841 m


1,190' 363 m



Avg Grade (6°)


Max Grade (18°)

Dogs Leashed

Features Commonly Backpacked · Fishing · Geological Significance · Lake · River/Creek · Swimming · Views · Wildflowers · Wildlife

Wilderness permits are required, but there are no quotas for the trail leaving Lake Edison. Campfires are not allowed above 10,000 feet or at Frog Lake or any of the lakes in the Margaret Lake area.

Need to Know

At least in mid and late summer, there is no water between the creek at 8900 feet and Frog Lake.


The trailhead is at 8070 about 5 miles up the Onion Spring OHV Route.That road is rated easy for vehicles with good clearance and 4-wheel drive. If you don't have 4-wheel drive, you can hike up the road. I was not the only one who did this, because as I was hiking down the road I met a pair of backpackers hiking up.

From the trailhead, the trail climbs steadily up the hill under a coniferous forest. At 8,900 if crosses a stream, which in mid-season is the last water source before Frog Lake. There is a nice, sheltered little campsite here. The trails climbs up along the top of a ridge through a beautiful Juniper forest. By 10,000 feet, we move out from under the trees with continually increasing views of the surrounding mountains. At just over 4 miles we reach the high point of about 10,550 feet. From there we have a 270 degree panorama of much of the Ansel Adams Wilderness. On a clear day, the views would be spectacular.

The USGS topo map shows Arch Rock as being below the trail just before the high point. This is incorrect. To reach the arch, continue north. The trail drops about 250 feet and then climbs about 40 feet to another saddle. At this saddle, the arch is partially visible. It is about 75 yards to the left (southwest) up an easy sandy trail. It is a good place to camp. There is a wide area that is relatively flat and sheltered by large rock formations. No fires are allowed, and there is no water. See the "Arch Rock" Gem for more details.

From Arch Rock, the trail drops until at 5.1 miles and 8800 feet it meets the Rock Lake Trail #26E02, which heads west towards Rock Lake. The Margaret Lakes trail wanders around ridges with minor ups and down for about 1/2 mile to Frog Lake. This beautiful lake with great campsites would make a good hiking target itself, but, if you have gone this far, you really should head on to Big Margaret and Rainbow Lakes, the most superb lakes in the area. Coyote Lake has good fishing and is also worth a visit.


Shared By:

Lee Watts

Trail Ratings

  4.0 from 2 votes


  4.0 from 2 votes
5 Star
4 Star
3 Star
2 Star
1 Star
Trail Rankings


in California


5 Views Last Month
387 Since Aug 22, 2020
Difficult Difficult



Arch Rock and some of the formations around it. The soft granite in the surrounding area has been scoured by the wind.
Aug 23, 2020 near Mammoth…, CA
Arch Rock in the morning light. The opening is about 30 feet tall and the entire formation may be 40 - 50 feet tall.
Aug 23, 2020 near Mammoth…, CA
Frog Lake
Aug 23, 2020 near Mammoth…, CA
There are many Western Junipers scattered along the top of the ridge leading up to Arch Rock
Aug 25, 2020 near Mammoth…, CA
North and northwest section of 270 degree view. On a clear day, the views from here would be truly spectacular. Mt. Ritter is on the right. Behind Pincushion Peak in the center is Clover Meadow area and the ridge with Isberg Pass.
Aug 24, 2020 near Mammoth…, CA



Current Trail Conditions

Add Your Check-In



Join the Community

Create your FREE account today!
Already have an account? Login to close this notice.

Get Started