Horse Flats Climbing

Last Updated: Aug, 2026
711
Ascents
306
Boulders
Guide moderated by James March

ABOUT Horse Flats

This digital Horse Flats climbing guidebook gives you GPS navigation, verified topos, and beta for hundreds of climbs. Explore classics and hidden gems with offline access to maps, directions, and beta videos. Whether it's your first visit or fiftieth, KAYA makes your Horse Flats days smoother, safer, and more dialed.

From author and original Horse Flats developer, James March: Horse Flats has been a unique bouldering destination for Southern California for over fifty years. It consists of a boulder-strewn mountainside above an idyllic campground with the summit of Mt. Hillyer, just over 6,000 feet.

I first visited Horse Flats in the fall of 1992 while living in L.A. I came armed with my first edition copy of the Southern California Bouldering Guide, a few apples, trail mix, water, shoes and chalk bag (no crashpad). I had no expectations for the area aside from some vague directions to... Show more
This digital Horse Flats climbing guidebook gives you GPS navigation, verified topos, and beta for hundreds of climbs. Explore classics and hidden gems with offline access to maps, directions, and beta videos. Whether it's your first visit or fiftieth, KAYA makes your Horse Flats days smoother, safer, and more dialed. From author and original Horse Flats developer, James March: Horse Flats has been a unique bouldering destination for Southern California for over fifty years. It consists of a boulder-strewn mountainside above an idyllic campground with the summit of Mt. Hillyer, just over 6,000 feet. I first visited Horse Flats in the fall of 1992 while living in L.A. I came armed with my first edition copy of the Southern California Bouldering Guide, a few apples, trail mix, water, shoes and chalk bag (no crashpad). I had no expectations for the area aside from some vague directions to the boulders and grainy black and white photos. But as soon as I emerged alone from my car I was hit with a sudden sense of peace and beauty. The wind seemed to whisper melodies through the Jeffrey Pinetrees and I took a rewarding breath of smog-free air. As I walked up the steepening trail from the campground, the boulders started to reveal themselves as statuesque granite sentries protecting a hidden mountain garden. Their colorful granite hues and multi-featured edges, created a perfect bouldering garden for me that day to explore, climb and simply kick back and give thanks. Located at the far Northeast end of Los Angeles County, Horse Flats is a popular hiking, climbing and mountain biking area in the San Gabriel Mountains. The area is also known for its high quality granite bouldering with a concentrated circuit of boulders and problems of varying style and difficulty. Remember that the Stonemasters who developed Horse Flats, brought with them no crash pads, only the skills and bravado for climbing the classics. Many of these original problems and boulders were not named so I have titled them with self-explaining references such as East Face or Right Arete, in an effort to make this guide easier to navigate. The early 90’s had the first crash pads available, but bouldering was not popular then and for me I practiced alone mostly because I couldn’t find others as psyched. After climbing alone for a while I came to prefer it. I was on my own time and rhythm. I meticulously brushed holds and thought through sequences and down climb scenarios, risking an unspotted fall, the rewards of my ascents were amplified and often mystical. With the advent of larger crash pads and climbing gyms, standards rapidly evolved and the potential for higher and harder boulder problems still exist. Many of the older highballs were established on top rope but are typically bouldered now. Please keep safety in mind on your visit, and remember the closest hospital is more than an hour’s drive away. Apart from the bouldering, the Top Rope Wall and the Pie Slice has a collection of nice routes, a few of which can be led on traditional gear. Not many bolts exist so most anchors need to be natural, (ie. sling trees and rocks). The first humans to live at Horse Flats would be the Gabrileno Indians. They frequented the area using the now famous Silver Moccasin Trail which now starts in Chilao to the South and becomes the Main Trail to the boulders at Horse Flats Campground. In those days both the Black Bear and the long extinct California Grizzly were at the top of the food chain. The name Horse Flats is in reference to the land being used in the late 1880’s by Horse thief and bandit, Tiburico Vasquez. He and his band of outlaws used the hidden meadows as pasture for their stolen horses. With the boulders surrounding Tiburcio like a fortress, he terrorized the lowland ranches for years until his eventual capture and hanging in 1875. CAMPING: The yellowish-orange and gray boulders lie above a shady campground with 26 sites; each has fire rings, picnic tables, communal restrooms, but no water. There is a 14 day limit to the unreserved camping and the cost is $12 a day. Senior or Access Interagency Pass discount $6.00. Additional vehicles add $5.00. The day use fees are the same as camping. If you don’t want to pay then you can park outside the campground and hike an extra ½ mile. Note: The campground is closed and gated through the winter months so this is the approach. SEASON: Horse Flats is typically known as a cooler season destination for bouldering. It can be hot in the summer days and buggy, though evenings and early mornings are still pleasant. The nights can be very cold as well so prepare appropriately. ETHICS: Horse Flats is home to many species of plant and wildlife so be aware of your impact. Please pack your trash and brush your tick marks, come in peace and leave rejuvenated. Horse Flats is accessed from Los Angeles from the 210 freeway. In La Canada take the 2 (Angeles Crest Highway) for 27 miles taking a left on Sulphur Springs/Santa Clara Divide Road. Drive another 2.5 miles until the campground entrance appears on your left. The Top Rope Wall Area can be accessed also by driving another 0.5 miles up the road to park at Rosenita Saddle and hike in from the broad summit of Mt. Hillyer (about 20 minutes). Parking is not allowed along the road past the Horse Flats Campground entrance gate. Do not park in campsites unless you have paid and are camping there. Park at the Rosentia Saddle Trailhead, then either take that trail to the northern boulders, or walk back down to the Horse Flats Campground to access the main boulders. Currently there are no access issues to Horse Flats but remember you are sharing the land with others so be mindful of mountain bikes and runners on the trail. The erosion has gotten worse following Hurricane Hilary in 2023 and the base of many problems have receded, so pad up accordingly. Also please respect your surroundings and don’t garden or overtly alter the landing zones. You may notice a few holds on boulders have been reinforced with glue. This was a method for keeping key holds from breaking, and used in the early days but not anymore.

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Recent Ascents in Horse Flats

KAYA CLIMBER
CLIMB
DETAILS
DATE
JACOB STUCKI
@stucki_onthewall
Thin Crack v0
felt v1 to me with the sit start, maybe because of my height. stacked a pad and it went in the next couple attempts. exit right for full points.
★ 5(v1, Solid)
8.5.2026
TONY S
@TonyTonyTony
Nipple Eraser v2
Felt as hard as other 3s in the area like Refrigerator and the sit to Mr. Peanut. That bread load pinch is so good.
(v3, Solid)
7.2.2026
TONY S
@TonyTonyTony
Swiss Cheese v0
Right exit V0
(v2, Solid)
7.2.2026
TONY S
@TonyTonyTony
Swiss Cheese v0
Left exit
(v2, Solid)
7.2.2026
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Areas in Horse Flats

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