Backpacking to Thousand Island Lake

Thousand Island Lake
Thousand Island Lake

Southeast of Yosemite National Park, nestled deep within the Ansel Adams Wilderness in California’s Sierra Nevada Mountains, there is a lake with many islands. Thousand Island Lake, or Islet Lake as John Muir called it, is all that remains of a glacier that once stood in its place. Behind the lake are Banner Peak, reaching 12,942 feet in elevation and Mount Ritter slightly behind Banner Peak, topping out at 13,149 feet. Scattered throughout the lake are small islands, some connected and some not; this is how Thousand Island Lake got its name. What follows is my story of our journey to this spectacular and photogenic place.  (The most exciting part of my story is of the Chinese rocket we saw entering the atmosphere. Keep reading!)

Why pick Thousand Island Lake versus all of the other magnificent alpine lakes in the Sierras? My father-in-law and brother-in-law hiked the John Muir Trail a few years ago and the area of Thousand Island Lake was their favorite part of the entire 215 mile hike. It didn’t take much to convince us it was worth the trip.

Thousand Island Lake
My husband, myself, brother-in-law, daughter, father-in-law, and older daughter are ready for our big hike.

We began our journey at Mammoth Lakes, California – a ski town that stays active and open in the summer with biking, hiking, family activities, and more. In order to get to the trailhead for the Thousand Island Lake hike, we had to park at the Mammoth Mountain Adventure Center and buy a ticket to catch the shuttle bus to Reds Meadow/Devil’s Postpile. There is no other way to the trailhead than via the shuttle.

Thousand Island Lake hike
In line for the shuttle bus at Mammoth Mountain

Aboard the shuttle with packs in hand, we got off at the first stop – Agnew Meadow (If you go, be sure to hold onto your ticket for the return trip on the shuttle!) There was a short walk from the bus stop to the trailhead, where a pit toilet and water pump is located. Here, signs point to trails in every direction. Bring a map to be sure you’re on the right one!

Thousand Island Lake

The path was a dusty and sandy one in places, with most of it being a one person wide path. There are horse stables in Agnew Meadows and there was plenty of evidence of horse presence on the trail; this became slightly aggravating when you’re looking for a stable place to place your feet. The River Trail, which was our trail of choice, follows the middle fork of the San Joaquin River. The PCT would take us to Thousand Island Lake as well, but as it was the higher trail and in the sun, we opted for the lower elevation.

There were places with shade throughout the hike that we savored. As it was late July, the temperatures soared during the day into the 90’s. The beginning of the hike had an up and down path that was more descending at first, with a 400 feet elevation loss over the first two and a half miles. Some areas of the hike were shaded in the meadows with lush foliage and wildflowers; other areas were out in the sun, covered in rocks, and dry foliage. Nowhere did I feel like the path was too perilous, exposed, or dangerous for myself, my husband, and my 2 daughters (aged 15 and 12).  The River Trail was well maintained and a great trail for my girls – no scrambling nor climbing necessary. The trail’s difficulty was rated ‘moderate’ online, for the 16 miles roundtrip hike and 4,560 total feet in elevation gain. Check out Modern Hiker’s information on the hike here. (Click on the images for captions.)

Despite walking the River Trail and hearing the river rushing, you can only see it in a few places. One of these places where you could view the San Joaquin River was our lunch spot. Not only was it incredibly scenic, but it provided us a good source of water that we could filter. (All water along this trail and at Thousand Island Lake should be filtered).

The hike didn’t really become too challenging until the last two miles, due to the elevation gain and hiking with less oxygen. Considering we had come from Death Valley (and Badwater Basin at 282 feet below sea level) the day before and started the hike at 8,300 feet, we were definitely not acclimated. The thin air proved to be more of a nemesis than the constant incline with every step. Our highest elevation point was 9,800 feet (around mile 8), when we finally reached the top of the trail and could see Banner Peak in our sights.

We were all pretty spent by this point – hot from the high temperatures, deficient in oxygen, high on fatigue, but finally getting a glimpse of Thousand Island Lake brought us all a rejuvenated spirit. We had made it! However, we weren’t done with the hike. We still had to hike about another mile to a mile and a half to get further around the lake to find a campsite (Campsites are on the north side of Thousand Island Lake). You have to camp at least 300 feet from the outlet of the lake, and you want to hike a bit to get away from all of the other campers. The further you go around the lake, the more privacy you will have. It’s not easy to keep hiking after a long day climbing up, especially when you’ve reached your destination, but it will ultimately result in a better camping experience. I was amazed at how many people were camping at the lake on the day we left. We passed a few larger groups of campers. We were so glad that we had hiked the extra mile just to find some solace. Once we settled in, we were ready to eat and rest!

Thousand Island Lake
My hubby and I at Thousand Island Lake

We spent our second day on a day hike around the lake, although we were specifically walking towards Banner Peak. Walking along the lake is easy, with mild ups and downs as you walk over large boulders and rocks. (I would recommend bringing hiking poles for the day hikes here.) When you reach the back of the lake, you escape from other hikers and can fully immerse yourself in nature. Small streams flow from the high peaks, from their melting snow and ice, and eventually drain into Thousand Island Lake. Banner Peak actually has a few glaciers on it, although they are not very big.


Basic Information for Thousand Island Lake:

  • Obtain a wilderness permit – If you heading into the backcountry for more than a day hike, you must obtain a permit to camp. This is for camping any time of year. Rangers enforce where you set up camp, making sure you are away from trails and water sources (200 feet).
  • Leave No Trace – Like all wilderness areas, Ansel Adams Wilderness follows the “leave no trace” policy where all trash must be packed out. As there are no pit toilets, be sure to follow proper guidelines for digging cat holes and burial of waste.
  • Filter all water – Even though the water sources are likely clean, always filter to be safe.
  • No open fires – Campfires are not allowed.
  • Proper food storage is required – Bear canisters are a necessity here. My brother-in-law had a close encounter with a bear sniffing his head while he slept on a boulder (without a tent). Fortunately, he woke up and scared it off. He heard the bear scamper off and later heard pots and pans jingling at another campsite. Keep the bears, and your party safe, by properly storing all food and scented toiletries. For more information, click here for Inyo National Forest permit information.

The night sky in the Ansel Adams Wilderness was absolutely amazing. We watched the stars come out as the sun dipped behind Banner Peak and the temperatures plummeted. Eventually the sky darkened and became illuminated with millions of stars, and the Milky Way made its appearance.

Thousand Island Lake
My husband’s photo of the night sky at Thousand Island Lake and Banner Peak.

The Chinese Rocket!

We have to thank my brother-in-law for even seeing the rocket in the first place, so many thanks to him! He was sleeping on a large boulder, without a tent, and was able to see the whole thing, from start to finish. He shouted to his dad to wake up (who was asleep in his hammock/tent), and I got out of our tent to see what the fuss was about. We saw what we thought was a meteor, incredibly bright, slowly moving across the night sky, breaking up as it continued descending.  It was moving so slowly – we couldn’t grasp why, but it was fortunate because it gave us time to wake the rest of our group. We eventually heard a boom after the meteor was gone, assuming it had landed somewhere. Obviously, since we didn’t have cell phone service out in the backcountry, none of us had our phones out or accessible to take a shot of this once in a lifetime experience.

Thousand Island Lake chinese rocket re-entry
What we saw in the night sky.

When we entered back into civilization, we learned that the fireball was not a meteor but a Chinese rocket that had re-entered Earth’s atmosphere. The CZ-7 rocket had launched about a month earlier for research purposes. I imagine the noise we heard was perhaps a sonic boom from the rocket.

All in all, it was a spectacular experience, and one that we’ll always remember.  Click here to access a news source with video of the Chinese rocket re-entering our atmosphere.

On our last day, when we hiked down from Thousand Island Lake, we were attacked by numerous flies and mosquitos. We encountered some flying insects on the way up, but the way down was much worse. Also, the further down in elevation we were, the worse the bugs. Due to this, no one wanted to stop for a significant break or lunch, because despite having bug repellant on, they were still swarming. Be sure to pack plenty of insect repellant!

The following are the rest of our photos of the lake. This area of the Sierras is so incredibly scenic, untouched, and amazing in stature. Being so removed from society and becoming in touch with nature was something we all benefitted from.

Have you ever been to Thousand Island Lake? Let me know in the comments!

Happy Travels!



  1. Alex B | 23rd Aug 16

    Beautiful photos and great write-up of a spectacular area! We were also camped at Thousand Island Lake on the night of the fireball. Four of us were up watching the stars from a granite dome overlooking the lake when we noticed a bright light approaching from the west. Initially we thought it was a helicopter or plane with a bright spotlight, but as it got closer we saw the “spotlight” was actually a glowing tail on a huge fireball. It was a truly amazing, jaw-dropping sight to cap off 4 days backpacking in a spectacular area.

    Here is another video taken from the Alabama Hills:

    • Julie | 24th Aug 16

      That was an amazing video! The people on it said the same things we did when we saw it. It’s funny that you thought it was a helicopter or plane with a bright spotlight. My brother-in-law, that spotted the fireball first, said the exact same thing. He thought there might have been a search and rescue operation going on at first. Needless to say, we both got to experience something truly magical! 🙂

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