Beartooth Plateau High Route

3 Boys, 300 Lakes, and a 3,000,000 Boulders

During my extended road trip of 2018, the last stop was supposed to be the Beartooth Mountains, situated on the Wyoming/Montana border just outside of Yellowstone. Unfortunately, Kylie broke her foot on the Grand Teton and the Beartooth fell out of the plans. As I began to plan out my 2020 road trip, my thoughts drifted back to the Beartooth. Reading about Nate Bender’s superhuman effort to climb all 27 12,000 ft peaks in the range in a single push only added fuel to the fire to get out and experience the Beartooth.

Logan moved to Bozeman recently and has been exploring the local mountains. We were both excited by the prospect of traversing the Beartooth Plateau, a unique high plateau of alpine lakes. So we drew an approximate route from Beartooth Pass to the Aero Lakes and decided to give it a go. We felt like it would be the perfect warm up for the bigger Wind River High Route next.

Day 1: Beartooth Pass to Flat Rock Lake

It was weird to step out of the car in such a completely alpine landscape. The Beartooth Highway itself is a beautiful scenic drive. We left a car at one of the pullouts and immediately found ourselves in alpine tundra, wildflowers, and stretching views. It could not have felt any further from the Cascades.

Sam’s first steps in a new world.

A short climb brought us to the top of the plateau. That was it – no bushwacking, no washing machine, no muddy climber’s trail, no devil’s club. Just a little 20 minute walk and we could see miles and miles of high alpine terrain. Our route across the spine of the range looked beautiful and simple, albeit a bit rocky.

A preview of our route.

The high plateau alternated between flat tundra and flat boulder hopping – not the fastest terrain, but not really challenging.

He’s a Montana Boy (say it with an accent) now.
Mirror tarns all over the ridge.

There was a surprising amount of running water coming out of springs in the ground. There were still also quite a few snow patches, even on the drier (eastern) side of the range. Many of the steep couloirs dropping off to the north were still snow filled.

Lots of this.
Something so peaceful about this place.

The Beartooth is, in many ways, an inverted mountain range. The low mountains are incredibly steep, vertical walled canyons. But the peaks are massive flat plateaus.

Photo opportunity spotted…
Beartooth Butte in the foreground.

As we crossed the state line, we began to get a view of the high granitic part of the Beartooth Plateau. This part of the plateau trades green parklands for a intricate plateau of granite hummocks and sparkling lakes. The size of this plateau is impressive and the number of lakes numbers in the hundreds. It is like the upper Enchantment Lakes Basin but 100 times the size and with 100 times fewer people. Nothing even in the High Sierra can compare in scale.

The endless expanse of the Beartooth Plateau.

At this point, it was time for us to leave the crest of the plateau and enter the maze land of lakes.

Logan demonstrates proper boot skiing form.

We made our way down to Jasper Lake and then started weaving across plateau. Every few minutes (at every lake), we were faced with a decision: left or right. We quickly learned that:

a. There are many more lakes than shown on the map.

b. Getting around a lake is not as simple as it looks on the map.

c. Green, if possible, is your friend. Boulder hopping gets old fast.

d. When in doubt, go right.

Typical terrain.

We passed a few other parties camping in these lakes, but found fewer as we got higher. Off trail travel is so simple here and the lakes are so beautiful that on one hand it is surprising there are so few people out here. But then you remember the non-infinite number of people living in this part of the world and the infinite number of lakes and it makes sense. Math.

Storm clouds gathering in the distance.
Pilot and Index across the valley, two peaks we would become familiar with.

Our maps did not really show the names of most of the lakes, so we made up names: Blue Lake, Deep Lake, Mirror Lake, White Rock Lake. The actual names were not much more creative. Our camp destination was Flat Rock Lake.

Flat Rock Lake and Castle Mountain.

Flat Rock Lake has a beautiful turquoise glow from the glacial melt above from the Castle Mountain Massif. Somewhat inexplicably, there was not a flat rock anywhere near the lake, so I’m not sure what people were thinking when they gave it that name. I have to say, we were a little disappointed.

Hanging at camp.

We had a chill evening dodging the mosquitoes, which were plentiful, and hiding from the occasional raindrops, although it never really rained much. A dozen lakes in the bag and still plenty of a money in the bank, not bad for day one in the Beartooth.

Day 2: Flat Rock Lake to Fossil Lake

We woke at first light and departed camp with light packs. Our plan was to summit Castle Mountain (12,612 ft), the fourth tallest peak in the Beartooth and all of Montana.

Heading up the creek to Varve Lake.

Above Varve Lake, we had to climb up some tricky slabs beneath the permanent snowfield. Who needs breakfast when you have the slabbage patch?

Varve Lake in the background, slabbing.

At the snowfield, we put on microspikes. Without spikes, the 30 degree snow would have been a no-go this early in the morning.

Just above the snowfield.

We continued up boulders until cresting the massive summit plateau. Now we were really confused: which bump is the highest? Dang flat mountains!

Sam crossing the summit plateau, with Pilot and Index behind.

After some wandering, we found a point with a cairn and we were satisfied. To the north, the flat summit plateau dropped off into a vertical thousand foot cliff. The Beartooth is truly a range of extremes.

Sundance and other Beartooth peaks.

We walked over to the other side of the plateau so we could actually get a view towards Castle Rock Spire. One of the many downsides of flat summit plateaus, especially one this high, is that you don’t get 360 degree views because most of the terrain is actually below the horizon!

Castle Rock Spire and its dying glacier.

I believe the little glacier here is the largest glacial remnant in the range. The extent of the glaciers drawn on USGS mags is quite large in places in the Beartooth, but in reality, they are almost all gone. The next time I come, permanent ice might be erased from this range.

Logan stands king of the castle.
Cautiously descending the snow, which had softened just enough.
Nice glacial hue to Varve.
The beautiful stream that flows from Varve to Flat Rock.
Near the inlet of Flat Rock.

After packing up camp, we continued on our migration westward, bouncing over bumps, hopping by lakes, marveling at the pristine landscape.

Cladocera Lake?
I guess we could call this one Iceberg Lake.

Once again, we vastly underestimated the complexities of the micro terrain. Although flat, there were many times more lakes than shown on the map, and thus many more passes. Line of sight was often only 20 minutes or so. We would crest one little pass only to find another beautiful unnamed lake. We nicknamed these false passes “Half-ass Pass.” Except for the slushy snowfields, almost all the travel was boulder hopping, which fatigued my hip flexors. Honestly, it was some of the most mentally tiring terrain I’ve crossed, partly because we were suffering from decision fatigue in the meandering micro terrain. I also had a bit of a headache, likely due to the altitude.

Our friends Pilot and Index off in the distance.
Arriving at the impressive Snowbank Lake.

We took a nice lunch break at Snowbank Lake and I started feeling better.

Horseshoe Lake??

There was a lot of buildup for the Red Rock Lakes. They did, in fact, have some pinkish reddish rocks. Enough to warrant the name? Not sure…

Ah, the dropoff to nothingness.

The terrain started to change eventually, becoming more grassy. It was a welcome change after endless boulder hopping. Finally, we crested “the last ass pass” and our line of sight went from minutes to days.

An unamed lake, Fossil Lake, and some mega peaks behind.

The sudden reveal of the range was truly incredible. Glacier Peak and Mt. Villard towered in the distance. We walked around this little lake and found a nice campsite on a grassy bench high above the massive Fossil Lake. Perfection.

Logan admires the view from camp.

This was one of the most memorable camps I have ever had: a slight breeze, minimal bugs, endless vistas, running water, and soft ground. The lake carved out a complicated shape in the parklands beneath, with numerous islands and peninsulas. Behind, a wall of big 12ers (12,000 ft peaks) provided a dramatic contrast to the fairytale like landscape before us. Slowly, the hours ticked by, until darkness rose like a curtain all around us.

Wonderful alpine meadows.
Sunset over Fossil Lake.

Day 3: Fossil Lake to Exit

Around midnight, we were rudely awakened by a noisy family of goats. They had come for our pee. They were running around about 100 ft away, snorting loudly. I have never heard them so agitated. I figured they would get their salt and move on, so I put in some ear plugs and went back to sleep.

However, the goats did not leave. Instead, they just came closer and closer. During one period, I could hear them breathing literally just outside the tent. We tried everything: we yelled, flashed lights, jumped out of the tent and stood tall, but nothing would deter them. They were way too close for comfort. We debated throwing rocks and using bear spray if we were charged, but did not want to harm them. They seemed unusually bold and aggressive. Finally, just a little before sunrise, the sounds went away and we could go back to sleep. What a bunch of annoying goats! This was definitely the worst nighttime animal disturbance I have ever experienced, worse than the snafflehounds on Stuart, worse than the bear that climbed on top of my car at Whitney Portal. Lesson learned: don’t pee anywhere near camp.

Sunrise on Glacier and Villard.

At sunrise, the air was perfectly calm and the light was warm. Was it just a nightmare? No, the grass was torn up all around our camp where the goats were seeking the salt. But all food and other items were perfectly untouched.

Mt. Wilse basking in morning light.

The sunrise was about as beautiful as it gets. After the goats, this was definitely not my top backcountry campsite. But at least the sunrise made up for it a little. At least one thing has to go wrong on a trip of this length, right?

The full extent of our cathedral.
Glad to finally be in the light.

We wandered down to the shores of Fossil Lake and found a way to rock hop across one of the narrower sections. Despite the endless water crossings and lakes (so numerous we did not carry any water, we just drank whenever we needed it) we were actually able to keep dry feet throughout most of this trip, which is a huge bonus when high routing.

You guessed it – Pilot and Index.
Mirror Lake???

We walked up an easy grassy valley before turning right to a high pass. Here, we gained our first clear views of the legendary Sky Top Valley, gateway to Granite Peak, the highest point in Montana.

Hiking towards Villard.

The Sky Top Lakes are a series of absolutely picturesque chained lakes guarded by steep chossy peaks. The scale is quite a bit larger here than the rest of the Beartooth Plateau.

The Sky Top Lakes in the calm morning light.
More of the same. Meh.

After much debate about the exit route, we decided to cross over a pass to the Aero Lakes. This afforded us a prime view of Granite Peak.

Thar she blows.

We were glad we chose the Aero Lakes, because the view above Upper Aero Lake was amazing!

Are we still on Planet Earth?

On the shore of Upper Aero Lake, we passed through swarms of thousands of gnats! They were so dense the sky turned dark. None of them bit, fortunately.

Upper Aero Lake with Glacier Peak and Villard.

The Aero Lakes took forever to traverse around, boulder hopping into oblivion. At this point we just wanted to get to yummy food and the threatening morning rain showers only increased that sense of urgency.

After Upper Aero Lake, the terrain changed like a light switch had been flipped. Gone were the granite boulder lined lakes. In were the grassy meadows, soft streams, and for the first time all trip, a trail and a forest. It took us three days to reach tree line, but damn it, we made it. It could only mean that the end of this fine adventure was truly near.

Looking Back

I really enjoyed our Beartooth Plateau High Route. This range does not get much attention nationally, but really impressed me. The density of alpine lakes is certainly far greater than anywhere else in the country. These lakes also make high route travel a bit more tedious with extensive boulder hopping. Nothing is ever that hard, everything will go, but nothing is fast. That’s how it goes in the Beartooth.

The most impressive part of this route, to me, was the solitude. Each little lake basin felt like its own little world. And for the better part of 3 days, on an August weekend, we saw not another single party. The ethos of this region is to be quiet and tread lightly. That’s why I didn’t get a super specific route description and please don’t ask for a GPX track; I don’t have one. This is a wonderful, unspoiled place ripe for adventure. Protect it and enjoy it!


  • Our route (excluding Castle Mountain) was about 38 miles and 8k gain. It felt a lot harder than that.
  • Footwear… I think burly running shoes were once again perfect. Ultra raptors are the king of high routes.
  • Weather worked out for us, but be prepared for pretty harsh, unpredictable storms up in the alpine.
  • Mosquitoes were not too bad, but definitely a nuisance at certain elevations.
  • Microspikes were not needed except on the climb of Castle. Every other snowfield was low angle or softened midday. That being said, there was a surprising amount of snowfields on the second day to cross. Our feet got soaked.
  • Don’t pee near camp. Just don’t do it.

One thought on “Beartooth Plateau High Route”

  1. Great photos, and thanks for the trip report! This is one of a handful of areas in the Mountain West where I have spent very little time, mostly due to the extremely short season between mosquito hell and winter. I’ll have to check it out soon.

Leave a Reply

Your email address will not be published. Required fields are marked *