Backpacking the River Trail to Thousand Island Lake, Iceberg Lake and Ediza Lake will wind you up towards one of the most breathtaking mountain ranges in the Sierras, the Ritter Range. This loop is about 25 miles long and has an overall elevation gain of 4,665ft. The loop will go south on the John Muir Trail (JMT) from Thousand Island past Garnet and Ruby Lakes, before splitting off up to Ediza and Iceberg Lakes. Coming back down from the Lakes, you’ll pass Shadow Lake, a popular day hiking destination, before coming back to Agnew Meadows.
This backpacking loop has tons of options for day hikes or alternative routes, depending on what you are looking for. We started our route from Agnew Meadows but there are several trails in this area, like the High Trail on the Pacific Crest Trail, the JMT, River Trail, and Rush Creek Trail just to name a few.
There is also a longer loop you can do if you would like a longer route that passes a few more lakes. For this option, you can go up past Iceberg Lake to Cecile and Minaret Lakes before coming down into Devil’s Postpile National Monument.
This trail is also very close to another great Mammoth area backpacking trip, Duck Pass to Pika and Purple Lakes.
Permits are required for all wilderness trips taken in the Ansel Adams Wilderness and are issued by the Inyo National Forest Service.
For Backpacking to Thousand Island, Ediza, and Iceberg Lake, you will need a permit for the River Trail from Agnew Meadows. The River Trail area is considered to be a part of the Inyo National Forest reservation system and can be found at recreation.gov. 60% of the permits are available to the public 6 months ahead of time. In 2021, there are no in person walk-up permits. The entire process is online. On a rolling basis, the other 40% of permits open at 7am two weeks before the start date of your trip.
Check for your desired backpacking dates above on Outdoor Status or sign up to receive a push alert to your phone if your desired dates become available.
Permits for Thousand Island Lake are some of the fastest permits to go, so make sure you apply for them as soon as you can. If permits are booked for the River Trail you can start at an alternate trailhead and plan your trip accordingly:
→ Start on the Rush Creek Trailhead near June Lake. First night at Thousand Island
→ Start at Agnew Meadows on the Shadow Creek trail and do the loop backwards.
→ Start at Agnew Meadows and take the High Trail on the PCT north towards Thousand Island
While applying for a permits you will need to know:
→ Hike Start Date
→ Starting Trailhead (River Trail, Agnew Meadows)
→ 1st and 2nd Night Camp Location (Thousand Island & Ediza or Iceberg Lake)
→ Group Size (cannot exceed 15)
→ Hike End Date
→ Ending Trailhead (River Trail, Agnew Meadows)
→ Permitholders Contact Information
Prior to heading out to backpack Thousand Island, Iceberg, and Ediza Lakes, you will need to check in for your permit online or over the phone. Directions will be sent to our email along with your reservation from recreation.gov.
Important Trail Information
↟ Campfires are not allowed at Thousand Island, Ediza, Iceberg, Garnet, Ruby, Emerald, Badger or Clark Lakes. No campfires above 10,000 ft. Just plan on not having a campfire.
↟ Bear canisters are required
↟ There are areas at all of the lakes that you cannot camp near. There will be posted signs on the trailheads designating where these are.
↟ Thousand Island Lake is a POPULAR designation for everyone. Expect it to be busy unless you go towards the far end of the lake. Camping areas are pretty easy to spot, but get there early to ensure you get a good one
↟ Camp only on worn, durable surfaces that look like they have been camped in before. Do not set up camp on meadow areas (grassy and fragile) and make sure your camp is at least 100ft from trails, lakes or rivers. This means do not set up camp on the lake bed.
↟ Prepare for BUGS. If you have been wanting to try out that Moquitonator-5000, this is probably the trip to do it. Treat your clothes before you leave, bring supplies like bug nets or Deet, and brace yourself. If the weather is warm and the winds are calm, the likelihood for bugs to be bad is pretty high.
↟ Dogs are allowed in the Ansel Adams Wilderness.
↟ Drones are not allowed
↟ Make sure if you are taking a dip in any lakes you try and remove any bug spray or sunscreen from your body to keep the water from getting polluted. Some of these lakes are extremely cold, so proceed with caution. Health risks can occur if your body gets shocked by cold water.
↟ Road closures can affect the Agnew Meadows area. Make sure to check the road is open. There is also a shuttle that runs from the Mammoth Ski area to Devil’s Postpile that you can take.
↟ Recreate Responsibly, and Leave No Trace. Stay on trail, don’t cut switchbacks, pack out your TP and trash, and be a good nature-loving individual. There was a lot of human waste, TP, feminine products, and wag bags that were left out for all to see at Thousand Island Lake. Keep places beautiful by treating them like it’s your home, because it is.
My Favorite Packed Gear on the Thousand Island Lake Loop
- Sawyer Jungle Juice 100 Pump Spray Insect Repellent – 98 Percent DEET: 98 percent Deet might seem a bit extreme, but as someone who has tried most natural repellants and products on the market, I cannot go back
- ExOfficio Bugs Away Rhyolite Shirt: I have been in the market for a good long-sleeve hiking shirt for some time now, and this seemed to be a good time for it considering the liklihood of bugs and the weather advisory. This shirt did a great job at keeping the mosquitos off the upper half of my body, and its fibers are treated with permeterin-based technology. This shirt has a UPF Rating of 50, and I felt like the white color kept me cooler in the heat of the day. They are definitely on the more expensive side for just a shirt, but I am super happy with it so far.
- North Face Horizon Breeze Brimmer Hat: I have been needing a hat with a wider brim to bring on trips, and this one did a great job! Paired with a bug net, it protects my face and neck much better than a baseball hat would, and was snug enough that it didn’t come off in high winds throughout the day. I also love the color!
- Gregory Maven 55 Pack: (new backpack, who dis!) This was my first trek trying out the Gregory Maven 55, and my first experience with a Gregory Pack. It fits so much better than my previous REI Traverse 60 and is WAY lighter. The hip belt was comfortable without hurting my hip bones and the back support was breathable and well cushioned, a huge win in my book!
You can also check out a longer list of my Must Have Backpacking Gear on another blog post!
Trip Dates: June 19th, 2021- June 21st, 2021
Total Mileage: 26mi.
Trail Type: Loop
Trailhead: Agnew Meadows (near Devil’s Postpile National Monument) on the River Trail
We started our trip early with a trip to Vons for food and Black Velvet Coffee for some pre-trail caffine before driving up towards Mammoth Ski Area. The road to here had only recently opened, and there was about a 30 minute wait to get through the fee area (free if you have a National Parks Pass). From this road you can also access the Devil’s Postpile National Monument and Reds Meadow area, but you will take the first right at the bottom of the road for Agnew Meadows.
Once at the Meadow area, the parking was decently full but we found a narrow spot to fit the CRV. There was a bathroom and bear boxes at the trailhead, and tons of backpackers were out getting ready to leave for their weekend trips or passing through on the Pacific Crest Trail. Reid barely remembered crossing through here on his PCT trip in 2019, but said he recalled everything still being covered in snow when he passed through after the 4th of July. 2021 was a terrible snow year, but it makes an early start to backpacking season!
Once on the River Trail, the trail steadily climbed after the Shadow Lake fork. Most of our elevation came from this day and this portion, and the weather advisory said to be prepared for a chilling 90 degree temp. I stopped for water and breaks pretty often despite feeling good about the elevation gain.
There were also several groups of people we passed that forewarned us about the mosquitos, making sure we came prepared. I had only been thinking about mosquitos for the past month and stocked up on 98% Deet (literal poison, but effective) and a mosquito treated hiking shirt.
Once we were close to the top of the summit, after the River Trail met back up with the PCT, you could see the top of Banner Peak on the horizon. Coming down into Thousand Island Lake was breathtaking. The lake is much bigger than pictures make it seem, and the entire area is expansive. We got to the lake around 4PM and were met with a decent number of backpacking and hiking groups in the area. After finding a spot a bit higher off the trail, we settled down for an afternoon nap and a quick read before heading down to filter some water and take a dip in the lake.
I never wanted to say it out loud on the trip, for fear of jinxing myself, but the mosquitos were not as bad as I expected. Most of this I attribute to the higher-than-normal wind conditions we had, but I also noticed a ton of the mosquito swarms that I saw down by the water were male (the ones that don’t bite) and the females came out a bit later when the sun started to set.
It was the longest day of the year on the day we camped at Thousand Island, which meant sunset was at about 8:30PM. After running around the lake for an hour to capture the last bits of light on the peaks of the Ritter Range, we ended our night in the best way possible on trail, dark chocolate peanut butter cups.
The next morning I woke up to my sunrise-call alarm at 5am, and got up to find a spot. I wanted a high vantage point for sunrise, and found a lovely, vacated camping spot on a ledge with patches of wildflowers all around it. If I had known about this spot, I might have just set up here instead! The alpenglow on Banner Peak was incredible, and there were a decent number of backpackers that had also woken up to welcome the daylight. A few groups had set up their chairs and Jetboils for coffee and tea, and several other backpackers were already packing up camp to get a head start on a likely long trail ahead of them.
After making my own breakfast and tea, I sat on a rock near our camping site waiting for Reid to wake up from his sleep-in. We packed up camp around 7:30 and were out on the trail towards Garnet lake before the hour was up.
We were now on our way towards Iceberg and Ediza Lake on the John Muir Trail. We passed Ruby lake before reaching Garnet, a twin of Thousand Island, and made our way down for several miles to the bottom near the fork for Ediza Lake. It was just a few more miles up towards the lakes, and we were making great time. We reached Ediza Lake just before lunch, and a man greeted us as we came in. “Let me be the first to welcome you to Ediza Lake!” he said. We sat down in a shady spot to filter water and break out the bagged tuna before finishing the last mile to Iceberg Lake.
When we reached the Lake, we were the first backpackers to arrive so we carefully picked a shaded and protected spot in some trees (the wind did not die down until well after dark this day, so this was a huge blessing). There were large groups of day hikers coming and going over the pass to Minaret and Cecile Lakes, and to our surprise nearly ALL of them stopped to skinny dip in Iceberg Lake. Iceberg Lake is the coldest lake or body of water that I have felt in a long time, and still had a huge ice sheet in the middle of the lake as a testament. A minute of submerging your foot left it numb, so these dippers were next level.
Around 8:30PM again, I made my normal photography run around the alpine lake area, really focusing on the beautiful wildflowers that were starting to pop out around the lake. The next morning, as usual, I made those rounds again waiting for the alpenglow that I love.
We had an earlier start to this day and were on the trail around 7:30 with the expectation of a lot of downhills for the remaining 7 miles. We made it to Shadow Lake around 9:30, and stopped to swim in the lake for a bit to get a bit refreshed. This lake was already busy with day hikers, and several groups passed us on the trail donning full mosquito netting and a very familiar deet-scent.
Another steep downhill later, and a steady climb towards Agnew Meadows, we made it back to the trailhead! Without skipping a beat, as to not let the mosquitos at the meadows smell us, we packed up the car and headed down to Mammoth for some post-trail brews. A great end to one of the best trails I have backpacked so far.
Disclaimer: This post contains some affiliate links, which means if you buy something through those links my blog will receive a small commission at no extra cost to you. This helps me to create free resources like the one you just read, so thank you for the support!
Headed out on the trail soon and have a question? Have a really cool side trip suggestion or itinerary I should check out? Leave me a comment down below!