The Ediza Lake – Thousand Island Lake Loop is a top-tier backpacking circuit in the Sierra Nevada Mountains. Covering about 25 miles with 2,110 feet of elevation change, the loop is usually done in three days of hiking (not including any additional layover days). The loop starts and ends at Agnew Meadows, located near Devils Postpile National Monument and the city of Mammoth Lakes. The loop incorporates sections of both John Muir Trail and Pacific Crest Trail while exploring beautiful landscapes in the Ansel Adams Wilderness of Inyo National Forest. Several beautiful lakes can be found along this loop, including three absolute stunners, Ediza Lake, Garnet Lake, and Thousand Island Lake. Each backcountry lake is located below soaring snow-shouldered summits.
- Over 7.3 miles with 1,250 feet of elevation change
Set out on River Trail from Agnew Meadows. Hike down into a canyon to Olaine Lake and then take Shadow Creek Trail up to Shadow Lake and John Muir Trail. Take an upper section of Shadow Creek Trail up to Ediza Lake. Camp near the west side of the lake (per national forest restrictions). Consider an extension to Iceberg Lake.
- Over 7.95 miles with 1,130 feet of elevation change (including lots of ups and downs)
Hike back down to John Muir Tail and take this trail north over a 10,110-foot pass to Garnet Lake. Hike around the east side of this beautiful lake and go over a slightly higher pass to the north. Cruise past two smaller lakes, Ruby Lake and Emerald Lake, to reach the outlet of Thousand Island Lake where John Muir Trail is joined by Pacific Crest Trail. Take a use trail along the north shore of the lake to find a place to camp (at least a quarter mile from the outlet, per regulations) and enjoy amazing views over the lake.
- 9 miles or more with 1,515 feet of elevation change
Hike out along the lakefront trail to the junction between John Muir Trail and Pacific Crest Trail. Leave Thousand Island Lake on the eastbound section of Pacific Crest Trail called High Trail. Go through junctions with River Trail and three routes to Clark Lakes. Cross slopes on the northeast side of a broad canyon to return to Agnew Meadows.
This being a loop, it can be hiked in the opposite direction, which is just as popular with backpackers. Because only a limited number of overnight permits are awarded for each trail each day, availability can determine the direction that you take the loop. Here are two reasons that you may prefer to hike to Ediza Lake on day one and Thousand Island Lake on day two:
- One of the steepest parts of the hike lies between Garnet Lake and the pass to the south. If you hike the loop in a counter-clockwise direction, you’ll have to put in some good effort here and great views of the lake will be over your shoulder. Better to descend on this slope for head on views.
- High Trail delivers fantastic overviews of the scenery to the west. You might yearn for these panoramic views on your first day, but if you save this perspective for the final day, you’ll have a fuller appreciation of the terrain that you visited on the previous days. You’ll notice extra details based on those experiences and closing with High Trail lets you take in the sum of your backpacking accomplishment, which is a nice way to end.
Extensions & Contractions
Most of the hike is a loop, but it does include a spur up to Ediza Lake. That lake should not be missed, but it could be could be cut to trim the trek by over four miles. Conversely, the trip can be extended by a couple miles by hiking past Ediza Lake up to Iceberg Lake to set eyes on another gem of the Sierra below the Minarets. Several other variations exist as well.
What you should know before you go
Overnight camping is not permitted within 100 feet of lakes, streams, and trails. Camping is also banned in several areas along the loop. Camping is not allowed around Shadow Lake, along Shadow Creek, along the south and east sides of Ediza Lake, or within a quarter mile of the outlets of Garnet Lake and Thousand Island Lake. Check current restrictions when your obtain your permit.
A permit is required for any overnight trips in Ansel Adams Wilderness and a trail quota is in place. High Trail has a limit of 12 permits that can be reserved in advance along with 8 walk-in permits. Shadow Creek Trail (which starts with River Trail and heads toward Ediza Lake) has a quota of 18 permits that can be reserved and 12 walk-in permits. A separate quota is available for River Trail for those who choose to continue up that trail toward Thousand Island Lake. River Trail has a quota of 18 permits that can be reserved in advance and 12 walk-in permits.
Permits for Inyo National Forest trailheads can be reserved at recreation.gov.Walk-in permits can be obtained at Inyo National Forest Ranger Stations starting at 11 a.m. the day before the first day of your hike. Arrive earlier than eleven, take a number, and wait in line if you are determined to get a walk-in permit. Mammoth Lakes Welcome Center is the nearest Inyo National Forest Ranger Station. The center is open daily from 8 a.m. to 5 p.m. and distributes permits and rents bear-proof canisters. The ranger station is located at 2510 Main Street (Route 203) on the road into Mammoth Lakes.
While the permit has no cost (except an online processing fee), a fee is charged to take the shuttle or a vehicle on the road to Agnew Meadows. If you stay at a campground in the Reds Meadow Area during you visit (like Devils Postpile National Monument Campground), you are permitted to drive in and park at the trailhead. Those not staying overnight at a developed campground will need to park at Mammoth Mountain Ski Resort and shuttle in from there (get off at the first shuttle stop for Agnew Meadows). A $10 vehicle fee is charged to drive in. The shuttle charges by the individual (current pricing). From the Agnew Meadows Shuttle Stop, it is an additional 0.4-mile walk down a gravel road to the trailhead for River Trail.
The trailheads at Agnew Meadows have small parking areas, toilets, and bear-proof storage lockers.
Dogs are allowed on leashes on trails in Ansel Adams Wilderness.
Campfires are not allowed above 10,000 feet and in several other restricted areas due to wildfire danger.
While in the backcountry, food must be stored in approved bear-proof canisters.
Follow “leave no trace” practices when disposing of waste.
You may with to carry an SOS beacon and communicator like the DeLorme inReach Explorer.
Basic directions for the Ediza Lake – Thousand Island Lake Loop
- Begin up River Trail (Pacific Crest Trail) from Agnew Meadows
- Stay to the right through a junction where PCT breaks off toward Reds Meadow (0.9 miles)
- Descend into a canyon and stay to the right past another trail to Reds Meadow (1.55 miles)
- Pass Olaine Lake (2.15 miles)
- Turn left up Shadow Creek Trail (2.5 miles)
- Pass the outlet of Shadow Lake (3.85 miles)
- Turn right on John Muir Trail (4.55 miles)
- Turn left up the next stretch of Shadow Creek Trail to Ediza Lake (5.25 miles)
- Pass the outlet of Ediza Lake and continue up the trail (7 miles)
- Reach a junction with Iceberg Lake Trail (7.3 miles)
- Hike farther around the lake to potential camp sites (at least another 0.25 miles)
- Turn left up Iceberg Lake Trail to extend the hike to Iceberg Lake (an extra 2 miles round trip)
- Hike back down the trail past the outlet of Ediza Lake (7.6 miles)
- Turn left on John Muir Trail (9.35 miles)
- Cross a 10,110-foot pass south of Garnet Lake (11.65 miles)
- Cross the outlet of Garnet Lake (12.65 miles)
- Ascend to a 10,150-foot pass north of Garnet Lake (13.65 miles)
- Pass Ruby Lake (14.05 miles)
- Pass Emerald Lake (14.45 miles)
- Pass the outlet of Thousand Island Lake (14.9 miles)
- Reach the junction where John Muir Trail unites with Pacific Crest Trail (High Trail) by a trail along the shore of Thousand Island Lake (15 miles)
- Turn left to hike out along Thousand Island Lake for views and campsites (at least another 0.25 miles)
- Leave the lake and head east along High Trail (15 miles)
- Keep left past the top of River Trail (16 miles)
- Stay to the right past the westernmost of three trails up to Clark Lakes (16.3 miles)
- Stay to the right past a second trail up to Clark Lakes (17 miles)
- Stay to the right past the easternmost of three trails up to Clark Lakes (17.8 miles)
- Come to the end of High Trail at Agnew Meadows (23.75 miles)
With about eight or nine miles to cover each day, the trek should be achievable by most hikers. The loop is incredibly rewarding with impressive views on every mile and lakes that are true beauties. More thorough descriptions and photos of each segment of the loop can be found in individual trail reports. Ediza Lake – Thousand Island Lake Loop is broken into these highlights: Shadow Lake, Ediza Lake, Iceberg Lake (optional), Garnet Lake, and Thousand Island Lake.
To get to the trailhead: Take Route 395 to Route 203 and drive 3.6 miles to Mammoth Lakes. Turn right onto Minaret Road toward Mammoth Mountain. Reach the ski resort after 4 miles. Unless you are staying at a campground during your visit, park here and take the shuttle to Agnew Meadows. If you are driving in, go 1.4 miles past the ski resort to Minaret Vista Entrance Station where a 10-dollar fee is charged for each vehicle to continue down into the valley. Drive 2.6 miles down a narrow paved road to a horseshoe bend at the intersection with Agnew Meadows Road. Turn right and drive 0.4 miles to the trailhead at the end of the road (passing High Trail, 0.15 miles from the end of the road).
Trailhead address: Agnew Meadows Road, Mammoth Lakes, CA 93546
Trailhead coordinates: 37.682, -119.086 (37° 40′ 55.20″N 119° 05′ 09.59″W)
|Shadow Lake |
This 8.5-mile hike crosses a picturesque canyon and passes a plunging cascade to visit a mountain lake in the Ansel Adams Wilderness of Inyo National Forest near Mammoth Lakes.
|Ediza Lake |
This hike of around 15 miles round trip ventures above Shadow Lake along a creek to a beautiful lake below Mount Ritter and Banner Peak in the Ansel Adams Wilderness of Inyo National Forest near Mammoth Lakes. Ediza Lake is an excellent destination for backpackers.
|Iceberg Lake |
This short extension off the trail to Ediza Lake heads to a higher lake in a sublime setting below a ridge of steep spires called the Minarets.
|Garnet Lake |
This beautiful lake along John Muir Trail is 8.55 miles from the trailhead at Agnew Meadows, making it an ideal lake to visit on a backpacking loop.
|Thousand Island Lake |
This exceptional lake is a true gem of the Sierra and is 8.75 miles from the trailhead at Agnew Meadows via High Trail, a section of Pacific Crest Trail, making it a great destination for an overnight trek.
|Devils Postpile |
This 1 to 1.35-mile hike visits the columnar basalt cliff that Devils Postpile National Monument is named after, with top-down and bottom-up views of the impressive formation. The hike can be extended to include Rainbow Falls at the south end of the monument.
|Rainbow Falls |
This hike of 5.1 miles or more passes the Devils Postpile Formation to visit an attractive 101-foot waterfall with rainbows in its mist.
|Minaret Falls |
This 3-mile hike from Devils Postpile National Monument connects with Pacific Crest Trail to reach the base of a waterfall that tumbles and slides down a rocky slope.
|More trails in the Sierra Nevada Mountains |
Explore other destinations in Inyo National Forest and the rest of the range.
|Devils Postpile National Monument Campground |
This 21-site first-come first-serve campground provides camping in a pine forest next the Middle Fork San Joaquin River near the trailhead for Devils Postpile National Monument.