The Angeles Crest 100 Race Guide
The Angeles Crest 100 Mile Endurance Run is one of the oldest hundred-mile trail races in the United States, challenging runners with a rugged point-to-point course through California’s San Gabriel Mountains. This event is limited to 150 participants, making each entry highly coveted through a lottery process. Over more than three decades, the race has maintained its reputation for steep climbs, technical trails, and dramatic elevation swings that push athletes to their limits. The finish line at Loma Alta Park sits near the iconic Jet Propulsion Laboratory, offering a unique juxtaposition of wilderness achievement and cutting-edge science. Completing AC100 has become a badge of honor among ultrarunners seeking a storied and demanding mountain adventure.
When It Is Run
The AC100 takes place each summer on the first weekend of August, typically starting at 5:00 AM on Saturday and concluding by 2:00 PM on Sunday under a 33-hour cutoff. Early August weather in Southern California can range from cool pre-dawn temperatures in the 50s to scorching midday sun exceeding 90°F, especially on exposed ridges. Preparing for this heat shift means training in both summer warmth and nighttime chill, planning hydration to manage sweat rates, and practicing pacing under fluctuating conditions. Runners should plan for intense sun exposure on southern-facing slopes as well as sudden wind gusts on ridge lines. The summer timing also coincides with monsoon season risk, so lightning and afternoon thunderstorms are possibilities that require gear readiness.
How to Qualify or Register
Entry into AC100 depends on a December lottery system, and applicants must submit proof of finishing at least a 50-mile ultramarathon in the previous year. The registration window opens mid-September and closes after ten days, with lottery results announced in early October. Successful lottery entrants then have two weeks to complete payment and sign medical waivers; failure to meet this deadline forfeits the spot. A waitlist fills any last-minute withdrawals, and the lottery process ensures fairness for both elite athletes and first-time hundred-mile runners. Keeping qualification documents and credit card information ready before the lottery increases the chance of securing and confirming entry without delay.
Particular Challenges
Angeles Crest 100 demands conquering over 18,000 feet of cumulative climbing and more than 22,500 feet of descent over steep, rocky trails and high-alpine ridges. The ascent of Mount Baden-Powell reaches 9,300 feet, presenting thin air and rugged footing that tests both cardiovascular fitness and ankle stability. Descents can be equally punishing, requiring careful foot placement on scree slopes and loose rock to avoid ankle rolls. Day-night transitions add complexity, as darkness hides trail obstacles and heat builds on open slopes. The point-to-point format forces crews to leapfrog support, and long gaps between aid stations—up to 12 miles in remote canyons—demand carrying extra food, water, and emergency gear. Mental resilience is as critical as physical readiness when fatigue, altitude, and heat challenge every step.
Course Format
AC100 follows a classic point-to-point layout, beginning in Wrightwood and finishing in Altadena at Loma Alta Park. Runners navigate a single corridor along the Pacific Crest Trail, the Silver Moccasin Trail, and the Gabrielino Trail without retracing steps. This one-way format builds a sense of forward momentum but requires precise planning for crew shuttles and drop bag placement at key checkpoints. The finish at a park near JPL provides a festive, urban contrast to the primitive mountain mileage that precedes it. Point-to-point races emphasize logistical coordination as much as trail strategy, making crew planning and shuttle schedules integral to a smooth race day experience.
Elevation Profile
The AC100 course starts at 5,890 feet in Wrightwood, climbs steadily to Mount Baden-Powell at 9,407 feet, and then undulates through a series of high ridges and deep canyons before descending to 1,300 feet at Loma Alta Park. Total elevation gain exceeds 18,000 feet, while cumulative loss tops 22,500 feet. Major climbs include the iconic five-mile push to Baden-Powell and the steep ascent out of Cooper Canyon. The most precipitous drops occur on the return from Shortcut Saddle, where technical trails require careful braking to protect quads and joints. Runners experience both high-air-thin breathing challenges and hot-valley heat within a single 100-mile journey, demanding versatile conditioning.
Terrain Breakdown
Underfoot, runners encounter a mixture of 70 percent singletrack trail carved through pine and oak forests, 15 percent dirt double-track used by forest vehicles, and 15 percent paved or fire road segments near aid stations and road crossings. Rocky sections with granite slabs and loose scree challenge traction, particularly on descents and river crossings. Southwestern-exposed slopes can bake in the sun, turning sandy trails to dusty chutes, while north-facing slopes stay cool and moist under tree cover. Training on mixed surfaces and shoe selection for traction and protection are crucial preparation steps for handling AC100’s varied underfoot conditions.
Time Limit & Cutoffs
Runners must reach the Loma Alta Park finish by 2:00 PM Sunday, 33 hours after the 5:00 AM Saturday start, to earn a buckle. Mandatory cutoffs at each of the fourteen checkpoints keep the race on schedule and ensure volunteer safety. For instance, Wrightwood departure gates close at 5:00 AM sharp, Inspiration Point has an 8:15 AM cutoff, and Vincent Gap requires passage by 9:20 AM. Later checkpoints such as Chilao, Red Box, and Mt. Wilson enforce progressively later deadlines into the night and early morning. Missing any cutoff results in disqualification, making early sections’ pacing vital to preserve time buffers for slower nighttime and late-race miles.
Aid Stations
The Angeles Crest 100 Mile Endurance Run features fourteen official aid stations spaced across the rugged point-to-point course, with the longest interval between stations reaching nearly twelve miles through remote canyons. Crews can access runners at seven designated crew points, including Chilao, Red Box, Vincent Gap, Islip Saddle, Cooper Canyon, Shortcut Saddle, and Mt. Wilson. Drop bags are allowed at each of these seven locations, giving athletes a chance to swap gear, nutrition, and cold-weather layers as they progress through the changing terrain and temperature zones. Volunteers staff every station with water, electrolyte drinks, basic first aid supplies, and calorie-dense foods like fruit, sandwiches, and soup. These strategically placed stops offer crucial respite and encouragement, breaking the 100-mile journey into more manageable segments that balance support and self-reliance.
Mandatory Gear
Every participant must carry essential safety and survival items throughout the entire course. Runners are required to have a reliable headlamp with fresh batteries to light the trail during pre-dawn climbs and nighttime descents, as well as a back-up handheld light. A waterproof breathable jacket and pants are mandatory to guard against sudden mountain storms, and an emergency bivy sack or space blanket ensures warmth in case of an unplanned stop. Athletes must also carry a whistle for signaling in rescue situations, sufficient hydration capacity for the longest aid-to-aid section, and concentrated electrolyte supplements to maintain balance. Race officials conduct gear checks at bib pickup and randomly at aid stations, and missing any item can lead to disqualification, underscoring the emphasis on runner safety in the challenging high-elevation environment.
Crew & Pacing
Support crews are welcome at the seven crew-accessible aid stations, but they must display an official AC100 crew credential and park only in assigned lot areas to protect fragile forest roads. Crews may hand off drop bags, offer extra clothing, and provide moral support, but they cannot provide assistance outside the designated points. Pacing is not permitted until runners depart Cooper Canyon (mile 52), and only one registered pacer per athlete may join the final miles to the finish. Pacers must carry the same mandatory gear as competitors and meet at the crew station to check in with race officials. Vehicle access for crews is strictly confined to forest service roads open to the public, and any unauthorized shortcuts or road use can result in time penalties or crew ejection, preserving the integrity of the wilderness course.
Navigation
The Angeles Crest 100 course is marked liberally with fluorescent orange flags, reflective pie-plates at junctions, and red glow sticks on overnight sections to guide runners through dense tree cover and steep ridges. Key intersections feature arrows painted on rocks or trees, and volunteers man every major turn to confirm the correct route. Despite robust markings, competitors are strongly advised to carry a GPS device loaded with the official AC100 GPX file, which includes all aid station coordinates and emergency exit points. Having a reliable navigation backup reduces the risk of wrong turns on technical singletrack, especially during pre-dawn hours. Familiarizing oneself with the course profile and key landmarks in advance helps runners maintain confidence and pace throughout the entire 100-mile route.
Finish Rates
Over its long history, the Angeles Crest 100 sees an average finisher rate of about 65 percent, reflecting the course’s sustained difficulty, high elevation gain, and temperature extremes. In cooler, dry years, finish rates can climb to near 75 percent as long as afternoon thunderstorms stay at bay, allowing runners to maintain steadier paces. Conversely, monsoon-season storms or record heat can drive the completion rate down to 50 percent or lower, forcing many athletes to withdraw before the final climbs. Most dropouts occur between Shortcut Saddle and Mt. Wilson, where fatigue, altitude, and technical trails amplify the challenge. Understanding these historical trends aids runners in setting realistic pacing and gear strategies to maximize their chances of reaching the finish line at Loma Alta Park.
Special Features
One of the signature rewards of AC100 is the handcrafted silver buckle awarded to those who finish within 24 hours, with a polished steel buckle for sub-30-hour finishers and a wooden medallion for all other finishers under the cut-off. The course’s alignment along the Pacific Crest Trail and Gabrielino Trail offers varied ecosystems, from chaparral slopes to alpine fir forests, making the scenery as memorable as the effort. The finish at Loma Alta Park, adjacent to the Jet Propulsion Laboratory, provides a striking contrast between natural wilderness achievement and scientific advancement. In recent years, the race introduced a “Spirit of the Crest” award to honor a runner or volunteer whose dedication exemplifies the supportive community ethos that underpins the event.
Previous Winners
Course records stand at 19:47:12 set by Zach Bitter in 2019 for men and 23:15:30 set by Pam Smith in 2018 for women, both marking standout performances on a notoriously punishing route. Elite repeat champions include Hal Koerner and Cassie Scallon, each with multiple podium victories that underscore their mastery of AC100’s relentless climbs and descents. Adaptive and nonbinary division records have been rising as the race embraces greater inclusivity, with athletes like Riley Brady and Alex Dixon earning rapid acclaim. The official results archive on the race website celebrates these champions and their diverse backgrounds, inspiring a new generation of ultrarunners to test themselves on the Angeles Crest trails.
Official Contact Info
For questions about entry requirements, course logistics, or volunteer opportunities, athletes and crew members should visit the official AC100 website at ac100.com or email the race director at info@ac100.com. The site hosts downloadable GPX files, aid station maps, mandatory gear lists, and real-time race updates during event weekend. Social media channels, including the AC100 Facebook group and Instagram page, provide additional community support and prompt answers to last-minute queries. Keeping these contact details close ensures smooth communication and quick access to vital information before, during, and after the race.