Thousand Island Lake from Agnew Meadows

Near: Mammoth Lakes
Trip Type: Backpack (2-3 days)
Distance: 18 Miles
Elevation: 8,300 - 10,000 ft
Vegetation: Pine Forest, Meadows
Last Visit: 7/4/16

Just over the Sierra Crest from Yosemite National Park lies the Ansel Adams Wilderness.  It is certainly one of the most beautiful places in California with high craggy peaks soaring over dozens of pristine lakes and cascading rivers.   The slightly hyperbolicly named Thousand Island Lake is a popular destination deep in the wilderness area.  We took a common loop there from Agnew Meadows via the John Muir Trail and the Pacific Crest Trail.  Along the way this route passes several other gorgeous lakes and waterfalls.  This loop would be doable in a long day hike, but it's more than worth spending a night or two at the lake and exploring the higher terrain.  It's a long drive from northern California population centers, but it's more than worth it.

Rules

This hike is in the Ansel Adams Wilderness, managed by the Inyo National Forest.  The permits are required for all overnight trips, subject to daily entrance quotas.  You can reserve them at Recreation.gov, but only far far in advance.  Search for Inyo National Forest Permits.  For this hike permits for the River Trail, the High Trail and the Shadow Creek Trail will work. A large portion of permits are held for walk-ups at nearby ranger stations.  Each day, passes for the next night are released at 11AM and are often gone by the end of the day on weekends.  No permits are required for day hikes.  Dogs off leash under voice control are OK. 

Trailhead:

Agnew Meadows trailhead just outside the Devils Postpile National Monument.  The road into Reds Meadow Valley is closed to private vehicles between 7am and 7pm.  The park service has intentionally worded their information to make the rules unclear to encourage shuttle use, but if you show up before 7AM you can drive in and park overnight at Agnew Meadows. That is, assuming you can get a spot.  It was already filling up when we arrived at 6AM.   If you show up after 7, then you'll need to buy a ticket on the shuttle into the valley. Dogs are allowed on the shuttle, but a muzzle is required.  Pet stores in Mammoth Lakes make a nice profit on this of course, so you'll have no problem finding one.

Route:

Caltopo Map: http://caltopo.com/m/T9EJ

Day 1: River Trail, Shadow Creek Trail and JMT

We headed out on the River Trail, descending slightly into the valley to Olaine lake.  At this point the forest is surprisingly dense given the scrubby landscape you drive through on the way to Mammoth Lakes.  The landscape traps alot of water running off from the higher elevation snowmelt, which is great for those of us who prefer forests to deserts.  However, on this hike in mid-summer we found the most mosquitos I've yet experienced in California.  It was the first time this Minnesota boy has used bug repellent in this state.

The River Trail

Olaine Lake

Anyhow, past Olaine Lake, we hung a left to climb up west side of the valley on the Shadow Creek trail.  After climbing along some small waterfalls and cascades here, you reach the outrageously beautiful Shadow Lake with Mount Ritter looming above.

The Shadow Creek Trail

The Shadow Creek Trail

Shadow Lake

After Shadow Lake, the Shadow Creek Trail joins the JMT for two miles of steady climbing with occasional views of high peaks to the south.  The trail tops out a bit over 10,000 ft then drops few hundred feet to Garnet Lake.

The JMT north of Shadow Lake

Garnett Lakae

The trail then loops around the east end of Garnet Lake and makes it's final climb of the day up a few hundred more feet over a minor ridge.  As the trail descends to Thousand Island lake you pass a couple of smaller lakes, Ruby lake and Emerald lake.  Ruby lake looked like an inviting spot just tucked away enough that you might have it to yourself, unlike most of the other high lakes in the area.

Bridge over Garnett Lake outflow

Ridge overlooking Garnett Lake

Ruby Lake

Emerald Lake

And finally you reach Thousand Island Lake in the shadow of Banner Peak to the west.  If you're overnighting, you won't be alone.  Thankfully the lake's shores are gently sloping with enough boulders and shrubby trees that the tents can be tucked away out of sight, so the lake feels uncrowded.

Thousand Island Lake

Day 2: The High Trail

We returned to Agnew Meadows via the high trail.  The first few miles roll down the junction of the river trail, before climbing back to around 9600 feet.  Where you get the first of many views down Reds Meadow Valley.





From there the trail drifts up and down a few hundred feet, but stays essentially level as it cruises southeast along the valley wall.  The first part of this section crosses a swampy section around the Badger lakes, then several large meadows. Towards the end of this high section, you get a spectacular view across to Shadow Lake a couple of miles to the southwest and a thousand feet below you.

Looking across to Shadow Lake

For the last few miles, the trail plunges steadily down to Agnew Meadows.

Agnew Meadows from the High Trail

Addendum: Thousand Island Lake to Lake Catherine (Glacier Pass)

After we dropped our tent at Thousand Island Lake, we went wandering up to Lake Catherine, in the col between Banner Peak and Mount Davis.  There is no established trail up this pass, but the open terrain was easy to navigate and there are some use trails visible for portions of the climb.  We saw a few other folks poking around up here as this is a popular off-trail side-trip.

The western slopes above Thousand Island Lake

The approach to North Glacier Pass

Staying to the north and west of the creek draining the pass seemed the smoothest approach, crossing smaller feeder streams but never crossing the main stream until fairly high up.  When we reached the headwall of the small valley leading to the pass, there was a large remnant snowfield, which was tiring to trudge up, so we made the mistake of making for the first dry rock we could reach.  This turned out to be an unstable talus slope though, and pretty sketchy.  If you come up this way make for the lowest notch towards the left side of the pass and use the snow as long as possible if it's not too icy.

North Glacier Pass just before Lake Catherine.  Watch out for loose rock.

Navigation and altitude concerns aside, the snow, talus and later rock-hopping up at the pass will be a bit much for many dogs and some humans.  Don't get yourself or your friends into anything you can't handle.   The lake is very nice, though.

Lake Catherine

Sadly it was getting a bit late and we were pretty beat.  If we'd had more time and energy we might have attempted to continue all the way up Banner Peak.  If you're up for a scrambly loose-rock adventure, the trip from Thousand Island Lake to Banner Peak would make a great middle day in a three day trip.

Marmot!