Deer Lakes Trail + Duck Lake Pass: Backpacking Mammoth Lakes

Mammoth Lakes, California is one of many beautiful portals into the Eastern Sierras. Backpacking the loop from Deer Lakes Trail to Duck Lake Pass will give you a small glimpse into this magical alpine wilderness!

Growing up, my family taught me to ski in Mammoth Lakes on our annual winter ski trips. As an adult, I’ve discovered downhill mountain biking, rock climbing, and backpacking. As such, my love for the Eastern Sierras has grown to encompass all four seasons. Two weeks ago (September 2024), I got the chance to return the favor and share a summer alpine adventure with my mom! 

We began at Deer Lakes Trailhead, hiked up 2,933 feet in altitude and traversed 16 miles over the course of four days, sleeping at over 10,000 feet each night. We crossed Mammoth Crest, Deer Pass, and Duck Lake Pass and explored at least a DOZEN alpine lakes along this incredible loop!

Due to a poorly timed snowstorm, a bear spray incident, and a sinus infection, we had quite the adventure, but I already can’t wait to return next year!

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Why Did I Choose Deer Lakes Trail?

I knew I wanted an Eastern Sierra backpacking trip, but didn’t know where to go. There are SO MANY options to choose from within Inyo National Forest alone—almost too many options. Since I only booked the trip one month in advance, some permits were already sold out which helped narrow my choices to a few trailheads within a reasonable drive from Los Angeles.

I then looked at hiking options originating from those trailheads on Alltrails and picked the one that seemed like the least elevation gain/distance and the most rewarding campsites. I also wanted a trail that my mom could physically do and that would leave time to explore on our short itinerary. 

I chose Deer Lakes Loop because a loop always sounds more exciting to me, and because it seemed to fit the criteria! The loop can either begin at Deer Lakes Trailhead (commonly known as Crystal Lake Trailhead) or Duck Lake Pass Trailhead, but the latter seemed to sell out of permits more quickly, so I chose the road less traveled in case changes had to be made (which they definitely did).

Our planned route for Deer Lakes Loop
Deer Lakes Trail
Backpacking at elevation was tough!

How to Book Permits for Deer Lakes Trail

Deer Lakes Trail falls within the John Muir Wilderness area of Inyo National Forest, and the forest service does a great job of updating their website with all the information you need for a successful backpacking adventure. They do NOT, however, monitor their phone lines very well. Make sure to read up on regulations and fire restrictions before you go.

For example, fires are always prohibited on most of Deer Lakes Loop because Deer Lakes and Duck Lake Pass lie above 10,000 feet in elevation. There are also other areas along the trail/near certain lakes where camping is prohibited, so make sure to do your research before booking your trip.

Click on the links below for more information:

Inyo National Forest Permits 

Inyo National Forest Website

When to Backpack Deer Lakes Trail + Duck Lake Pass Trail

I’d personally say late August or September is the best time to backpack Deer Lakes Loop.

Having grown up on the southern California coast, I’m definitely sensitive to both cold and elevation. Even though I take plenty of trips to the mountains, I have existed basically my entire life at sea level and even work on the ocean. I wear snow jackets on summer evenings. I’m a total wimp.

That being said, the only thing I hate more than the cold is the mosquito. Even though September can get pretty chilly at elevation, I’d still prefer to carry more layers than hide inside the tent all evening as clouds of mosquitos swarm. One night it dipped below freezing, but my thermal pjs, 15° sleeping bag, and Nalgene of boiling water kept me cozy enough!

I can probably count on one hand the number of mosquitos I saw the entire trip, and for that reason, I will always book my Eastern Sierra backpacking trips in September! As much as I’d LOVE to see high Sierra flower blooms in spring, I’d rather not see them through a mosquito net. I’ll save that for the day hikes!

Additionally, I didn’t want to worry about residual spring snow on trail. However, the weather can be unpredictable in early fall. Ironically, we had to postpone our trip by six days because of an early season snow storm. Six days later, we enjoyed a dry trail with sunny 65°F conditions with a slight breeze to top it off—perfect backpacking weather!

duck lake pass trail
Exploring Duck Lake was worth all the hard work!

Day 1: Backpacking Deer Lakes Trail

Hiking Deer Lakes Trail (aka Crystal Lake Trail)

Our first day was a doozy.

I woke up at 4am, picked up my mom from her house near L.A., and drove five more hours through the Mojave Desert for an arrival time of 10am at Lake George. I’d planned to arrive early since I knew the hike would be pretty brutal. 

We’d have to climb from the Deer Lakes Trailhead, otherwise known as Crystal Lake Trailhead, at 9,000 feet to Mammoth Crest at 11,000+ feet, then descend into Deer Lakes Basin six miles later. It might not sound too bad for the average mountaineer, but for a couple of unremarkable backpackers from sea level with 40lb packs, it was definitely a challenge!

We began hiking around 11am. I would have liked to spend a night acclimatizing to the elevation, but unfortunately our busy schedules didn’t allow for that, so off we went! Or should I say UP we went, one little step at a time. The trail was easy enough to follow, but for us it was very slow-going.

Deer Lakes Trail
Deer Lakes Trailhead
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Climbing high over Mammoth Lakes Basin

Hiking Mammoth Crest via Deer Lakes Trail

As the elevation on Deer Lakes Trail got higher, the views over Mammoth Lakes Basin just kept getting better! Eventually, we stopped for a snack around 1pm before beginning the final climb up and over Mammoth Crest. We caught a glimpse over the east side of the crest and spotted some lingering snow in the rocky chute beneath us before beginning our descent to Deer Lakes.

deer lakes trail
The final ascent up and over Mammoth Crest at 11,000+ feet in elevation

Finding a Campsite near Deer Lakes Trail

As we descended, it became clear that there was quite a bit of open real estate around Deer Lakes Trail. We were the only people in sight! We found a nice flat spot with minimal vegetation overlooking the westernmost lake and set up camp for the night. 

After exploring more the next day, we found a few other prime campsites near the other large lake that would have been nice options, but there were a few groups that came through that area over the course of the day. It seems that lake is more popular since it’s closer to Duck Lake, and people seem to like to do day hikes up and over Deer Pass.

Deer Lakes Trail
Our stunning campsite at Deer Lakes

Day 2: Navigating Deer Pass to Duck Lake Pass

Quick Morning Walk up Deer Creek

We woke up to frost on our bear can, which meant nighttime temperatures had dropped below freezing. After having woken up at 4am the previous day, my internal clock got me out of bed at 3:45am—the coldest part of the night, so I decided to take some night photos. 

When it was time to crawl back in bed, I used my Jetboil to quickly reboil the water for my makeshift Nalgene sleeping bag heater and crawl back in bed to await the nice warm morning sun. If you’ve never felt the comfort of a hot water bottle in your sleeping bag on a 30°F night, you’re missing out!

After the sun finally rose, my mom and I took a walk around Deer Lakes to explore and we were not disappointed. Deer Creek was so pretty with the fall colors spreading across the grasses and bushes! We had to keep stopping for photos, even though they were all of the same view.

We found the second Deer Lake to the east as well as the trail we’d be taking over Deer Pass later that afternoon. It looked impossibly steep.

deer lakes trail
Easternmost Deer Lake
Westernmost Deer Lake at night

Hiking Deer Pass to Duck Lake Pass

After we ate lunch and packed up camp, (and I accidentally got sprayed with my mom’s bear spray and took an impromptu dip in the lake) we started up Deer Pass, only a little behind schedule. We only had to travel about two miles, but had to go up and over the highest elevation on Deer Lakes Loop: just over 11,200 feet. 

We passed the third Deer Lake, which was very pretty but a bit crater-like and too close to the trail to camp at. Here, we had our first good look at Deer Pass.

All I read on Deer Pass was that the trail was hard to navigate from the top of Deer Pass to Duck Pass. I read (or remembered) nothing of the steep “trail” up 500 feet of talus field to get to the 11,200 foot high point. The view was great but this was the most challenging hiking section of the entire Deer Lakes Loop, and my mom wasn’t super comfortable on this terrain.

I will say, it would have been much worse descending this section of trail, so I’m thankful we did the loop counterclockwise.

Once at the top, I wound through the trees over easy terrain, frequently referencing the trail and our location on my Gaia GPS app until we merged with Duck Lake Pass Trail.

The Deer Pass ascent is quite steep

Finding a Campsite near Duck Lake Pass

Since my mom was exhausted from the uphill talus slog and my skin was still burning from the bear spray incident and I wanted to swim before it got too cold, we set up camp near Duck Pass, about 100-200 feet up from the water level.

As soon as I could, I quickly scrambled down a steep, rocky hillside to reach lake level. Here, I marveled at the beauty and pristine clarity of Duck Lake as I washed off again and refilled our waters.

That evening, I decided to take advantage of the moonless night and take some more night photos over Duck Lake. Not only did I capture the Milky Way, but I also accidentally captured a rocket launch!

Duck Lake Pass Trail
Camping above Duck Lake
duck lake pass trail
Milky Way + rocket launch over Duck Lake
Clear skies in the Sierras!

Day 3: Hiking Pika Lake + Duck Lake Pass Trail

Hiking to Pika Lake via Duck Lake Pass Trail

Our second morning in the backcountry was stunning, and we started hiking pretty early because we wanted to check out Pika Lake. The trail was so vibrant with the fall colors and the turquoise lake! We took SO many photos, but eventually made it to Pika Lake.

Pika Lake was definitely the most beautiful lake of the whole trip with the crystal clear water and craggy mountain backdrop. We even found a little nook out of the wind, so I couldn’t help but go for another swim! 

The only thing that detracted from the lake a bit were the number of people we passed on the trail. The trail is a pretty popular day hiking destination. Even on a Wednesday in September, we passed at least 20 people on the short trail from Duck Pass to Pika Lake plus a half dozen tents at Pika Lake itself. We were grateful to have found a secluded site for our tent.

duck lake pass trail
Pika Lake Trail
duck lake pass loop
Pika Lake was the prettiest lake of the trip

Backpacking Duck Lake Pass Trail

After returning to camp and packing up, we left Duck Lake with the intention of camping further along Duck Lake Pass Trail to help cut down the hike back to the car the next day. We hiked up and over Duck Pass and descended roughly 1000 feet into the lakes basin below. After two miles and dozens of photos, we found a campsite in the towering pine trees at Skeleton Lake.

We turned in early as my mom was battling a pretty bad sinus infection, but we were woken up a few hours later by a bear alarm from our neighbors across the lake and shouts of “Go home bear!” which we both agreed was an ironic statement. We were never visited by a bear as far as I know. Maybe the lingering bear spray on my clothing kept them away. There was definitely more life at this lake than the others over the pass.

Duck Lake Pass Trail
Descending Duck Pass
Duck Lake Pass Trail
Skeleton Lake at sunset

Day 4: Exploring Mammoth Lakes Basin

After packing up and leaving our final campsite at Skeleton Lake, we had four miles left to hike back to the car. Along the way, we crossed Cold Water Creek and passed four more lakes, each worthy of their own backpacking trip! The towering pines that shaded this section of Duck Lake Pass Trail were a welcome presence on a nice sunny day, and were much appreciated after days spent among sparse alpine vegetation. 

We reached the car around noon and couldn’t help but take more photos of Lake George. It was cool to think about how far we’ve come since we camped at Lake George Campground years ago. Back then, backpacking wasn’t even on our radar, but I’m so glad it’s now something I can share with my mom!

Duck Lake Pass Trail
Emerald Lake was just one of 12 lakes along Deer Lakes Loop

Deer Lakes vs. Duck Lake: My Honest Opinion

Deer Lakes Trail
First look at Deer Lakes
duck lake pass trail
View from camp at Duck Lake

Honestly, I was pleasantly surprised by Deer Lakes. All the reviews I read raved about the beauty of Duck Lake, but didn’t mention Deer Lakes too often. As a result, I wrongfully assumed Deer Lakes were kind of a means to an end—a place to camp and refill water to break up a hike where Duck Lake was the star.

Instead, we found the lakes surprisingly picturesque (though not turquoise) with a stunning backdrop and the quiet isolation that you look for when backpacking! Although bigger and bluer, this kind of isolation is something Duck Lake cannot offer since it’s such a popular destination for both day hikers and backpackers. 

We saw only two groups at Deer Lakes, both at the easternmost lake, and both on the second day. In contrast, I lost count of the number of people we passed at Duck Lake and Pika lake. There’s a reason they’re popular, but they ARE popular.

Additionally, there isn’t a ton of flat ground surrounding Duck Lake itself, so most other campers chose to stay at Pika Lake instead. As beautiful as it is, we saw at least a half dozen tents near Pika Lake on our day hike, which would dissuade me from camping there in the future. I’m glad we pitched our tent where we did! 

I would definitely return to both locations in the future, but I’d have to decide if I’d prefer the prettier Duck and Pika Lakes, or the quieter Deer Lakes. Or maybe I’ll just do the whole loop again! Either way, I HIGHLY recommend backpacking in this area. It’s honestly incredible!

backpacking mammoth lakes
Completing the loop! One last photo at Lake George before returning to our car!

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