Browns Flat: Overnight 2026

TRs for the San Gabriel Mountains.
Matthew
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Post by Matthew »

Last year, Dima and I made it to the legendary Browns Flat and you can read all about it here!

This year, I challenged myself and my friends to do an overnight in the flat which proved to be the best camping spot in the San Gabriels. I dreamed of it for a whole year since the last trip, wondering what it would be like to go to bed and wake up with a snowcapped Mt. Baldy in front of me. I knew it was going to be tricky hauling so much water since there's no water anywhere around the flat but my dreams just had to become a reality.

The crew was Me, Wes, Nate and Dima. We picked this past weekend months in advance and doubled down on those plans when the forecast showed a random heat wave in the month of March. The lack of water for the 9.4 mile one way trip was going to be a big issue so we coordinated with Jeff to stash some water (2 gallons by the way) at the start of the ridge down to the flat. The route we planned was to start on our bikes at Cow Canyon Saddle and take Sunset Ridge Road all the way to Sunset Point. There, we'd stash the bikes at the start of the ridge and do the last mile and a half by foot, cutting the new growth with our loppers. One way would have a gain of 1640ft and a loss of 1900ft.
The Trip
I rendezvoused with Nate at Cow Canyon Saddle at 8am Saturday morning and heading up the fire road. Having not ever been on this road, it was pretty nice and easy to ride on a fully loaded, 63lb gravel bike. The road was lined on both sides and the middle with thriving poodle brush which made for some delicate riding to avoid making contact. I like to call poodle brush, "the forbidden kush" due to it's aroma closely resembling cannabis but with more exotic floral notes.
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The whole ride up to the high point was mostly shaded with some nice west moving breezes which kept us nice and cool. We couldn't have asked for better heat wave conditions for this part.
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Eventually we got to our first viewpoint of the flat, who i've missed so so much.
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Nate and I eventually made it to the ridge and started to head down. Since the last time I was up here, the trail remained intact but the brush now severely covered the path. We both brought our trusty Fiskars PowerGear® Super Pruners which made quick work of the manzanita, oaks, and whitethorn.
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Before we knew it, we were descending the trail down to the flat! This time, we took a different trail than the year before which proved to be the best way in. The brush was thick in some spots and kinda hard to follow but old 10+ year cuts in the trees showed us the way.
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Aaaand BOOM!
BROWNS FLAT REACHED!

We both cried out out victory calls and were welcomed with lovely echos from across the flat. It was much greener than last year with some nice patches scattered about. Nate and I had a few hours to chill before Dima and Wes would show up so we got our sleep systems set up and laid in the shade of the Ponderosas.
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Let's now talk about a crazy place called Peter Sinks and I promise we will get back to Browns Flat. Peter Sinks is a massive sinkhole in the mountains of Utah and is one of the coldest spots in the United States. The reason it is one of the coldest spots is because of a phenomena called cold-air pooling where cold air will settle into depressions like valleys or canyons during the night. We all notice this when we hike or camp on a mountain vs inside certain canyons but Peter Sinks is much MUCH more unusual. Peter Sinks floor is made up of limestone which isn't able to hold water, nor does it have a valley that could act as a slide for the cold air to run out of. According to wikipedia, Peter Sinks can hardly go 4 days in summer without hitting freezing temperatures at night.

Browns Flat is also subject to some interesting cold-air pooling since the center of it is at a lower elevation than the outflow in the north-western part of the flat. When Nate and I arrived, the temps were significantly cooler than the ridge line which was probably at 80F. Between the last trip and this trip I did a ton of research on cold-air pooling and convinced my friends that we'd want to bring warm-ish clothes for the overnight but we did not know how cold it was going to be.

Eventually, Dima and Wes emerged from the bushes and were welcomed with hugs and excitement! Nate brought some frisbees with him so we played frisbee golf and established the weather station on the opposite end of the flat as a hole.
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We got a few throws in until they landed in a beautiful grassy field where we decided to take a break and lay down in the shade.
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We did complete the game eventually but I cannot remember who won, maybe Nate? Who cares though. The beauty of this place was capturing us left and right such as this grass growing through an almost fully decomposed downed ponderosa.
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The evening approached as we continued to just take naps and chill under the shade of the trees. Having nothing to do in a breezy wonderful flat was just perfect enough for us. Wandering around looking at the stored acorns in woodpecker holes or the burnt stumps of ancient ponderosas was all that needed to happen that evening and for us 4 Eispiraten adventurers, the simplicity of the day was enough!

Before I knew it, my dream of watching sunset's colors cover Mt. Baldy came true.
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NOT SO FAST, YOU CAN'T GO TO BED YET, IT IS CURVEBALL TIME!

We were sitting together eating our dinner and drinking some beer looking over the flat and it's views when a sound sounded. All 4 of us recognized this sound but only Dima had the guts to call it out. Somewhere directly across the flat at roughly our elevation was a Mountain Lion making a mating call. Then, behind us and behind that ridge was the return call of another Lion. They went back and forth a few times and stopped. This was the first time any of us had ever heard a Mountain Lion call in all our combined years in the mountains around the world. The call could be described as fucking terrifying and sounds like a human woman screaming. Throughout our dinner session, the lion in the flat moved around by the direction of it's call. Throughout that night, I was woken up by our lion friend about 3 times, plus some foxes also making calls. If you know your John Bradford history, he was living at Browns Flat during the late 1800s and early 1900s UNTIL he was harassed by the local Mountain Lion Population. This snippet was taken from Trails Magazine, Summer 1938.
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We all quickly realized that Browns Flat was THEE hookup spot for Southern California Mountain Lions and I hope they can reproduce heavily in the near future!

And by the way, temps dipped just below freezing that night since there was ice on our sleeping bags and a sliver of ice in our water bottles, beating out every low temp of every weather station in the range! Talk about a MICROCLIMATE!
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We ate our breakfast in the morning and departed early (11am) to beat the heat. We took our time trimming lots of brush for future hikes and awaited arriving to Jeff's water stash. And he did deliver on some electrolyte filled water as well as some birthday cake cookies!
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I'mma leave you with our final pic of the flat on our departure.
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Browns Flat Is Amazing
Long live John Bradford Camp and Al Borak
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JeffH
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Post by JeffH »

I got a photo of the flat about the same time as your Baldy shot.
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Matthew
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Post by Matthew »

JeffH wrote: Mon Mar 23, 2026 8:26 pm I got a photo of the flat about the same time as your Baldy shot.
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Beautiful!
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drew
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Post by drew »

Great trip report, Matthew. It looks like y'all had a blast.
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HikeUp
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Post by HikeUp »

Too cool!

Great spot for capturing mountain lion activity with a trail cam.

Are those isolated trees dispersed through out the flat planted by man?

Can it fill up with water during extreme rain fall? Would such water percolate down through the soil before filling the flat to the point it would spill out?

What whiskey did you bring?
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dima
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Post by dima »

Wait, I don't remember being convinced to bring warm clothes. I didn't even bring my jacket! Brrr
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David R
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Post by David R »

Browns Flat is where the cougars hang out, interesting. One of these weekends that has cooler weather I need to get up there, will have to find where you made the cut. When I was up there years ago there looked like a good route without going all the way to the end of the ridge.
Matthew
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Post by Matthew »

HikeUp wrote: Mon Mar 23, 2026 9:44 pm Too cool!

Great spot for capturing mountain lion activity with a trail cam.

Are those isolated trees dispersed through out the flat planted by man?

Can it fill up with water during extreme rain fall? Would such water percolate down through the soil before filling the flat to the point it would spill out?

What whiskey did you bring?
1. All the trees that are in the flat are naturally there. I do believe they are the lowest elevation grove of Ponderosas in SoCal but I think Nate can correct me if im wrong.
2. It doesn't seem to be able to fill up with water. I have checked aerials after rainfall and it looks to just disappear. There are shallow channels and areas that are muddy so it's closer to a sierra meadow if anything.
3. The flat is 30 acres and very much a bowl with no outflow. Since no creeks or rivers flow into it, it would get all water from rain in which there isn't much of.
4. We brought 0 whiskey but I almost brought my flask of Jameson.

Total alc consumed are as follows:
Matthew: 1 sierra nevadas, 1 pint ipa
Wes: 3 sierra nevadas
Nate: 1 sierra nevada
Dima: 1 pint cider, 1 pint sour monkey
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Nate U
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Post by Nate U »

Great idea for an expedition, and your trip report covers it all very well!!! I had an excellent time.

A few bits to add:

• on the uphill gain portions of the Sunset Ridge Road route in, I tried for the first time a new bike-packing strategy of lashing my overnight pack onto the bike seat, and then just pushing the bike with my pack attached to it up the mountain. It worked great - my backpack weight became entirely wheeled weight, and simple machines won the day. Will be doing that again in the future.

• While we were within the Bridge Fire burn zone, the poodle dog growing right in the Sunset Ridge Fire road was insane. If anyone is wondering if the Bridge Fire window of pre-poodle dog has closed yet, it most definitely has. So far no terrible rash, but I had to very carefully step around the stuff for like 4 miles. Lots of unsuspecting Sunset Peak hikers and trail runners I think are in for it.

• Stashing the bikes in white thorn off sunset point to transition to brush warfare mode felt quintessential Eispiraten.
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• The route in had been trimmed in our day-expedition a year prior, and I'm sure since Al Borak's days there has occasionally been cutting trail along our route, but it was very overgrown and Matt and I did our fair share of cutting on the way in. We found a new route down off the ridge onto the flat itself, taking one into the bowl through a biomes that begin as predominantly White Thorn and Chamise along the sun-exposed ridge, through lots of Manzanita on the steepest upper sections, then transitioning into shrub oak and eventually a lovely but blow-down ridden California Bay woodland as we entered the cooler, wetter microclimate that is Brown's Flat. Eventually this gave way dramatically to the open mini-alpine Savana-meadow of the flat itself. There is absolutely nothing else like it in the San Gabriels.

• There is no litter, no fire rings, no tent sites, no human footprints. This place is PRISTINE. Only a little weather station. Wild.

• Matt and I spent most of the afternoon living the proper full-chill Brown's Flat Life. The primary activity was napping, interspersed with repositioning our sleep systems every hour or so to stay within the ever-shifting shadows of the towering relict Ponderosa Pines. One of the most peaceful spots I'ver ever been.

• That evening after Wes and Dima arrived, a Helicopter circled us overhead and (nearly?!) landed on the opposite side of the flat before disappearing again. We were NOT expecting that and I was wondering in the moment if our evening was about to take a very different turn.
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• Before we went to bed, and then at 3AM and 5AM, we could hear a mountain lion prowling the thick brush along the eastern edge of the flat. It was maybe 1/2 mile off, its chilling scream echoing around the bowl like a loudspeaker in stadium. It also seemed to emanate from the opposite side as well, so there may have been more than one communicating with each other? Does that happen? We felt a lot like John Bradford, thats for sure.

• Oh I should mention there is one ancient Ponderosa pine in the northeast corner that must be 100 years older than the rest. Its the largest of its species I've ever seen. Magnificent.

• Next morning I woke to an image of Baldy at sunrise and my sleeping bag covered in frost. It got COLD at night here - at the same 4,200 feet Baldy village registered a low of 58, while we were well into the 30s. My upper body was ok but my legs and feet were feeling it through the long night.
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• we cut our way out of the bowl and reunited with our bike's and Jeff's heroic water cache. I wanted to make a big satisfying end to my route down in the city, so I continued south along the fire road, clutching my brake on the epic 4,000-ft drop doing my best to stay under control. At one point around 3,000 feet I rounded a sharp bend to see a big washout cutting across the entire road and had to crash the bike to avoid going into it. Luckily just a scuffed knee and elbow. I could see the Ridgeline we cut our way along, hiding the flat on its opposite side:
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• By about 2,000 feet the lupine and other spring wildflowers became really beautiful. It also became REALLY HOT. When I finally stumbled down some switchbacks onto San Dimas Canyon Road in La Verne to reunite with the crew, it was in the 90s. A little different than the frost-covered sleeping bag on the flat that morning!

• After having spent time there, here is my theory as to why the flat exists the way it does:
~10,000 years ago there was a fairly typical small canyon/drainage with steep slopes, like one of thousands in the San Gabriels. But what was unique with this one is the the granitic gneiss that made up the slopes failed in a big, big way, creating a giant single landslide that slid to the Northwest directly from one side of the canyon to the other. What is also unique is this landslide got deflected by the opposite side of the canyon, and also by a bend in the canyon path that existed on its northern end, capturing enough of the landslide's energy that the debris failed to find an outlet for all the broken rock debris flowing into Fern Canyon below, instead just filling up this canyon in hundreds of feet of broken rock.
• As time went on the debris settled preferentially in its center where the material was thickest, forming a fully-enclosed basin where there was no water outlet. This meant all the silt and sand and organics stayed in place, and seasonal water evaporated in place, leaving behind all of its salt/mineral content, like a mini salt flat. The Ponderosa and probably other pines that were widespread at that elevation during the ice age happily grew in all of this soil, shedding their acidic needles onto the ground year after year without getting eroded away, making the soil both very acidic and very salty. As the climatic became hotter and dryer these unique soil conditions discouraged the brush from taking over the flat the way it did in the rest of the front range, and the cool air pooling microclimate Matthew explained allowed the pines to continue to grow in the flat while their friends got replaced by brush on the surrounding slopes.
• There are no sapling ponderosa pines in the flat now because in the last 100 years the climate has shifted enough further in the hot/dry direction that young pines can't survive. So it is only a small relict population of 21 (I counted them) adults who live on, a 30-acre pocket of a San Gabriel Mts that existed 10,000 years ago.
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