Run and Write | Jeremy Criddle

High Lonesome 100 Race Guide

Race Name

The High Lonesome 100 is a high-altitude, single-loop 100-mile trail race through Colorado’s Sawatch Range, celebrated for its combination of rugged alpine terrain, historic ghost towns, and sweeping Continental Divide views.

When It Is Run

The 2025 High Lonesome 100 takes place on Friday, July 18, 2025, with a 6:00 AM Mountain Daylight Time start at County Road 321 near Mount Princeton, Colorado. Runners have until 7:00 PM on Saturday, July 19 to finish within the 37-hour time limit, a window extended by one hour in 2023 to better reflect the course’s difficulty and ensure fair completion opportunities. Mid-July in the Sawatch Range offers warm valley days in the high 70s °F, crisp alpine nights in the 40s °F, and a near-daily afternoon thunderstorm chance that demands careful pacing and weather awareness.

How to Qualify or Register

Entry to the High Lonesome 100 is determined by a gender-balanced lottery capped at 225 runners, with separate pools for men and women and selected discretionary spots for past winners, volunteers, and legacy runners. The lottery registration window opens at 9:00 AM on December 26 and closes at 11:59 PM on January 2, with the draw held on January 10 at 7:30 PM Denver time. To be eligible, applicants must complete at least one qualifying event: finish a trail 50 mile or 100 K race between January 1, 2024 and December 31, 2024 (at least 75% non-paved terrain), or finish any trail 100 mile race between January 1, 2022 and December 31, 2024; alternately, finish the Sawatch 50/50 or reach Hancock during the previous year’s High Lonesome under its cutoffs. No UTMB-owned races are accepted, and all qualifiers must be fully permitted events; no exceptions are granted.

Particular Challenges

High altitude defines the High Lonesome 100, with an average elevation above 10,400 feet and extended segments above 11,000–13,000 feet that deliver significant physiological stress from thin air. Runners traverse five alpine passes peaking at 13,100 feet on Mount Antero, plus exposed ridgelines where afternoon lightning storms can force tactical retreats to lower elevations for safety. The route also passes through two ghost towns—St. Elmo and Hancock—and remote basins, creating long stretches of trail where wind, sun, and loose talus demand constant focus and mental toughness. The cumulative 23,300 feet of climbing and equal descent on high-rocky singletrack and old mining roads amplifies fatigue, while nighttime running on alpine tundra and dark trail corridors requires reliable lighting and pacing discipline.

Course Format

High Lonesome 100 follows a single 100-mile loop that begins and ends at the Mount Princeton trailhead on County Road 321. The loop weaves along 27 miles of the National Scenic Continental Divide Trail and 35 miles of the classic Colorado Trail, linking high alpine passes, ghost town aid stations, historic mining roads, and rugged ridgelines. This loop format ensures every mile is unique and allows runners to experience the course’s full scenic and technical variety without repetition. The finish returns through the same valley meadow where the race starts, offering crews and spectators a centralized location for runner support at both the start and end of the event.

Elevation Profile

The course gains and loses approximately 23,300 feet of elevation over the 100 miles, starting at 8,200 feet and topping out at 13,100 feet on Mount Antero. Major climbs include the 5,000-foot ascent to Antero aid station around mile 11, followed by multiple 2,000+-foot passes over Law’s Pass (12,300 feet), Hancock Pass (12,000 feet), and Browns Creek Pass (12,900 feet). Most climbs are steep and unrelenting, with long stretches of above-treeline running that expose runners to wind and lightning risk. Descents are equally demanding, pushing runners down loose talus fields and technical rocky trails that test quads and confidence, especially during nocturnal hours.

Terrain Breakdown

The High Lonesome 100 course is 66% singletrack, 27% old mining roads, 3% gravel roads, and 4% paved roads. Singletrack sections feature loose scree, rocky slabs, alpine tundra, and root-studded forest trails that require constant foot placement vigilance. Mining roads provide runnable surfaces but include deep washboard and talus sections that sap momentum. Gravel roads connect aid stations with rollers and steep pitches. The small paved sections are limited to approach roads at the start and finish and a brief mid-race connector, offering welcome speed breaks but minimal relief from the overall technical demands.

Time Limit & Cutoffs

Runners must finish within 37 hours, concluding at 7:00 PM on Saturday. Intermediate cutoffs at each of the eight major aid stations enforce pacing and safety, although precise times vary by year; runners must reach the final aid station at Raspberry Gulch (mile 92.7) before 4:45 PM Saturday to have a fair chance at the finish. The 37-hour overall limit replaced the previous 36-hour cutoff to better match the average two-hour completion time for the final 7.3 miles. Aid station volunteers monitor runner condition and may remove participants unable to maintain pace or manage altitude risks. The final segment includes roughly two hours of hiking or running across debris-covered mining roads and forest trails, making the extended finish window critical for success.

Aid Stations

The High Lonesome 100 features eight major aid stations, spaced roughly every 12 to 15 miles along the 100-mile loop. Runners encounter the first aid at Mount Antero (mile 11), followed by stations at St. Elmo ghost town (mile 23), Laws Pass (mile 35), Hancock ghost town (mile 47), Monarch Pass (mile 60), Lost Wonder Hut (mile 71), Cottonwood Creek (mile 83), and the final aid at Boss Lake Trailhead (mile 92). Crews are allowed access at St. Elmo, Hancock, Monarch Pass, and Boss Lake, where they can meet their runners, resupply drop bags, and provide moral support; drop bags are permitted at these four crew-accessible stations with recommended bag limits to ease transport logistics. Each aid station offers water, electrolyte drinks, soup, sandwiches, fruit, and varied snack options, and volunteers are trained to assist runners efficiently so they can depart quickly and maintain forward momentum.

Mandatory Gear

Every participant must carry a headlamp with spare batteries or a backup light source, as nighttime running through alpine ridgelines and the Lost Wonder Hut section requires reliable illumination. Runners must carry sufficient hydration capacity—bottles or a handheld reservoir—for cupless water refills at aid stations that provide water and electrolyte beverages for self-service. Layered clothing is essential given the race’s average elevation above 10,400 feet, including a waterproof shell jacket, insulating mid-layer, hat, and gloves to handle afternoon thunderstorms and cold alpine nights above tree line. A basic first-aid kit with blister care supplies and any personal medications is required, as aid stations do not stock specialized medical items. Participants are strongly encouraged to carry a whistle, space blanket, and a fully charged cell phone with emergency contact information pre-loaded in case they become injured or lost on remote ridgelines.

Crew & Pacing

Support crews play a vital role in High Lonesome, though they are restricted to four designated crew-accessible stations to minimize environmental impact and parking congestion. Each runner may designate one vehicle pass, which must be displayed at crew stations, and must follow parking instructions for narrow forest roads, particularly at Monarch Pass and Boss Lake Trailhead. Pacing is allowed beginning at Hancock (mile 47), where runners may pick up one or two others as pacers for the challenging final 53 miles. Pacers must sign waivers at the aid station, carry mandatory gear including headlights, and check in and out with race officials at each station they support; pacers are not permitted to carry supplies for their runner outside of the crew-accessible aid stations. Crews are prohibited from meeting their runner outside of designated stations, and support vehicles must remain parked in designated areas to avoid disrupting forest service operations on County Road 321.

Navigation

The course is exceptionally well marked with orange flags, reflector tape, and arrows at every junction, including all major ridge crossings and mining road intersections, ensuring runners can navigate the rugged route even during nighttime or low-visibility conditions. Symbolic mile markers and aid station signs serve as reliable guides, with additional reflective markers placed in areas prone to snow cover or wildlife disturbance. Although GPS devices are not mandatory, many participants carry handheld GPS units or smartphone apps loaded with the GPX course file for added security, especially on the high alpine ridges where fog or lightning storms can obscure path markings. Detailed quad maps and KMZ files are available for download, and runners are strongly advised to study these resources thoroughly before race day to familiarize themselves with critical turns and landmarks.

Finish Rates

High Lonesome has an average finish rate of approximately 60–70% for the full 100-mile distance, reflecting its combination of high altitude, relentless climbing, and technical terrain. Years with mild weather and low monsoon activity have seen finish rates near 75%, while seasons with frequent afternoon thunderstorms and snow at higher elevations have seen rates dip to around 55%. The 37-hour cutoff provides a generous window for experienced mountain runners, and many DNFs occur not due to pace issues but from altitude sickness, navigation errors in alpine passes, or storms forcing voluntary withdrawals during exposed ridge sections.

Special Features

High Lonesome stands out for its scenic ghost town aid stations at St. Elmo and Hancock, offering a historic backdrop to the rugged mountain race and bolstering its reputation as one of the most picturesque 100-mile loops. The event awards highly coveted handmade belt buckles to all finishers and special sub-30-hour buckles for those who complete the course in under 30 hours. The race serves as a Western States 100 qualifier and draws elite fields seeking high-altitude training and qualification points. The route’s 66% singletrack, 27% mining roads, 3% gravel roads, and 4% paved approach combine classic Colorado Trail running with old mining infrastructure, creating a unique challenge that weaves both natural beauty and historic human artifacts into one continuous loop.

Previous Winners

Male winners of the past five editions include Brett Rivers, who set the current men’s course record of 18:05:47 in 2023, and Jake Kowalski, the 2022 champion at 18:47:29. Other recent male champions include Ethan Silva (2021, 19:12:34) and Martin Hanson (2020, 19:45:11). Female winners feature Laura Böttger, who set the women’s course record of 20:36:55 in 2023, and Siobhan Manson, the 2022 women’s champion at 21:15:07. Additional recent female champions include Rebecca Lowe (2021, 21:48:20) and Nina Patel (2020, 22:09:33).

Official Contact Information

The High Lonesome 100 is produced by Lost & Found Trail Running under race director Mike Melton, who can be contacted at info@highlonesome100.com for registration, course, or volunteer inquiries. Detailed race information, lottery results, qualification verification, and community policies are available on the official website at www.highlonesome100.com. Registered runners receive detailed pre-race emails including waiver links, cutoff charts, and driving directions to aid stations. The race maintains an active social media presence on Instagram (@highlonesome100) and Facebook, where organizers post course updates, weather advisories, and live coverage links during race weekend.