Browns Flat
Posted: Mon Feb 17, 2025 5:07 pm
The following trip report is written from the account of my close friend who made the trip recently but does not have access to a computer to write it themselves.
I learned about Browns Flat many years ago while looking at a topo and it really piqued my interest since it is about 600 yards long and 200 yards wide, which is a gigantic area of flatness. To understand the scale of that area, it can basically fit 2 Rose Bowl stadiums side by side! We are all familiar with the geographical term of a “flat” and have a few of those places in these mountains, most notably, “Henninger Flats” or “Doe Flat” or “Supercloud Hollow.” Browns Flat is actually the result of a 10,000ish year old landslide, which was proven by some researchers at Cal Poly Pomona https://www.cpp.edu/sci/geological-scie ... Thesis.pdf. I highly recommend reading this thesis to learn more about the geological aspect of this feature. The flat contains an ancient grove of Ponderosa Pines that has shrunken in size over the century. I visited the Huntington Library to look at Will Thrall’s photographs from 1896 to see what the place looked like back in the day. The following photographs were taken on my iPhone with glare so the glare was retouched out for a clearer image.
From the North
Looking North, Mt. Baldy in the background
John Bradford’s Cabin with John and his horsey!
John downing some drank next to a big tree, note the graffiti
Browns Flat looking South
Thrall didn’t go into detail on who John Bradford was but one can assume he was just looking for a breathtaking spot to live.
They began their trip in the early morning at Potato Mountain trailhead. The air was crisp while the ground and vegetation was glistening from the previous night’s rainfall. The trail winds up to a firebreak that meets with Sunset Ridge Fire Road at an elevation of 4060ft. They then followed that road until it met with Sunset Point radio towers. From there, they had their first glimpse of Browns Flat further below. The path down to an old trail was relatively clear, with a few spots that needed brush clearing.
My friend followed an old road cut that was visible on LIDAR that met with the southern end of Browns Flat. They noted how brushy and slow moving this particular section of the trip was, with bits of crawling and brush surfing necessary. They eventually made it to the flat and were taken aback by how massive the flat was. They walked the entire perimeter and noted how empty yet beautiful this open space was, especially since the Angeles is so rocky and steep. Below are the photos they shared with me to post.
Sources
The Huntington Library. (n.d.). Will H. Thrall photographs, photCL 481, Box 1. The Huntington Library
Cortez, Robert. Geochemistry of Volcanic Rocks from the Cretaceous Metamorphic Terrane of the Eastern Mojave Desert, California. 2019, California State Polytechnic University, Pomona, https://www.cpp.edu/sci/geological-scie ... Thesis.pdf.
I learned about Browns Flat many years ago while looking at a topo and it really piqued my interest since it is about 600 yards long and 200 yards wide, which is a gigantic area of flatness. To understand the scale of that area, it can basically fit 2 Rose Bowl stadiums side by side! We are all familiar with the geographical term of a “flat” and have a few of those places in these mountains, most notably, “Henninger Flats” or “Doe Flat” or “Supercloud Hollow.” Browns Flat is actually the result of a 10,000ish year old landslide, which was proven by some researchers at Cal Poly Pomona https://www.cpp.edu/sci/geological-scie ... Thesis.pdf. I highly recommend reading this thesis to learn more about the geological aspect of this feature. The flat contains an ancient grove of Ponderosa Pines that has shrunken in size over the century. I visited the Huntington Library to look at Will Thrall’s photographs from 1896 to see what the place looked like back in the day. The following photographs were taken on my iPhone with glare so the glare was retouched out for a clearer image.
From the North
They began their trip in the early morning at Potato Mountain trailhead. The air was crisp while the ground and vegetation was glistening from the previous night’s rainfall. The trail winds up to a firebreak that meets with Sunset Ridge Fire Road at an elevation of 4060ft. They then followed that road until it met with Sunset Point radio towers. From there, they had their first glimpse of Browns Flat further below. The path down to an old trail was relatively clear, with a few spots that needed brush clearing.
The Huntington Library. (n.d.). Will H. Thrall photographs, photCL 481, Box 1. The Huntington Library
Cortez, Robert. Geochemistry of Volcanic Rocks from the Cretaceous Metamorphic Terrane of the Eastern Mojave Desert, California. 2019, California State Polytechnic University, Pomona, https://www.cpp.edu/sci/geological-scie ... Thesis.pdf.
