One hundred miles, many course models
100-Mile Ultramarathons
A fixed-distance ultramarathon where terrain, cutoff structure, night running, aid access, and crew rules can matter as much as the 100-mile label.
How the Format Works
A 100-mile ultramarathon covers approximately 160.9 kilometers, but the shared distance does not make every race operationally similar. A flat loop, a mountain point-to-point course, and a remote technical trail can demand very different pacing, equipment, support, and time on feet.
Most runners will encounter darkness, cumulative foot and stomach problems, changing temperatures, and hard cutoff decisions. The useful comparison is therefore not just distance: study the course model, climbing, aid gaps, crew and pacer access, mandatory gear, intermediate cutoffs, and withdrawal logistics for the exact edition.
Curated preparation path
Learn, Train, and Plan
Choose the Right 100-Miler
Match terrain, support, cutoff structure, and expected duration to your experience rather than choosing by reputation alone.
How to Choose Your First Multiday Race
Compare logistics, terrain, duration, support, and personal readiness before committing.
AnswerBest First Ultramarathon Distance
Use readiness and course demands rather than assuming one first distance suits everyone.
GuideUS 100-Mile Race Directory
Compare source-checked races by date, state, terrain, course model, and cutoff.
Build Durable Movement
Prepare to alternate efficient running and hiking while protecting enough capacity for the final miles.
Walking Strategy for Ultramarathons
Plan purposeful hiking before fatigue turns every walk break into an emergency response.
AnswerHow Long Does Ultramarathon Training Take?
Build a readiness timeline from current consistency, recovery, and race-specific demands.
GuideTapering for Ultramarathons
Reduce fatigue without trying to add last-minute fitness or unfamiliar routines.
Plan Aid, Fuel, and the Night
Rehearse the decisions that become harder when pace slows and darkness changes the course.
Crew and Aid-Station Strategy
Build efficient stops around the access and assistance the race actually allows.
GuideGut Training for Ultrarunners
Practice familiar foods, portions, timing, and fallback options before race week.
Gear guideHeadlamp and Battery Strategy
Match lighting, backup power, and beam choice to the route and expected hours of darkness.
Protect Feet and Decision Quality
Use practiced systems for friction, shoe changes, symptoms, and late-race judgment.
Blister Prevention
Reduce moisture, friction, pressure, and fit problems before they compound.
Gear guideFoot-Care Kit for Multiday Running
Prepare a small, tested response kit rather than improvising after damage develops.
ToolInteractive Gear Checklist
Build a personal list, then reconcile it with the current mandatory-kit rules.
Curated race directory
Selected Upcoming 100-Mile Races
25 matching events as of Aug 13, 2026; directory reviewed August 10, 2026.
Superior Fall Trail Race 100 Mile
Gooseberry Falls State Park to Lutsen, Minnesota, USA
A 102.9-mile point-to-point race on the Superior Hiking Trail, with technical singletrack, 17,350 ft of gain, and a 38-hour cutoff.
View verified race details →Wasatch Front 100 Mile Endurance Run
Kaysville to Soldier Hollow, Utah, USA
A 100-mile point-to-point crossing of Utah's Wasatch Range with roughly 24,000 ft of climbing, high mountain terrain, and a 36-hour limit.
View verified race details →Mogollon Monster 100
Mogollon Rim near Pine, Arizona, USA
A rugged 102.3-mile crossing of the Mogollon Rim with six major rim climbs, 15,900 ft of gain, elevations near 8,000 ft, and a 38-hour cutoff.
View verified race details →Run Rabbit Run 100
Steamboat Springs, Colorado, USA
A high-country Colorado 100-miler based in Steamboat Springs, with separate Hare and Tortoise divisions and division-specific 30- and 36-hour limits.
View verified race details →Flagstaff to Grand Canyon Stagecoach Line 100
Flagstaff to Tusayan near Grand Canyon, Arizona, USA
A 100-mile point-to-point Arizona Trail race from the Flagstaff area toward the Grand Canyon, with roughly 7,000 ft of gain and a 31-hour solo limit.
View verified race details →Mountain Lakes 100
Olallie Lake Resort, Oregon, USA
A remote 100-mile Cascade trail race based at Olallie Lake, with rocky mountain terrain, Pacific Crest Trail miles, 11,700 ft of gain, and a 30-hour cutoff.
View verified race details →Showing the next 6 races here; use the full directory for all 25 active or upcoming records. Dates, entry status, routes, and rules can change. Use each event page's official organizer links before registration or travel. Format preparation paths were reviewed August 10, 2026.
100-Mile FAQs
How far is a 100-mile ultramarathon in kilometers?
One hundred miles is approximately 160.9 kilometers. The organizer's measured course may be slightly longer or use a named 100-mile category, so check the published exact distance.
What is a typical 100-mile race cutoff?
There is no universal cutoff. Course difficulty, remoteness, elevation, permits, and aid logistics all affect the limit. Compare both the finish cutoff and every intermediate gate on the current rules page.
Is a 100-mile race the same as a 24-hour race?
No. A 100-mile race ends when the runner completes the course inside its cutoffs; a 24-hour race scores how much distance the runner covers before a fixed clock expires. Some festivals offer both options on one course.
Compare Related Formats
Fixed-Distance Multiday Races
A broad family of continuous races where the finish line is fixed but the distance, duration, terrain, and support model vary widely.
24-Hour Races
A fixed-time race where the clock runs for one full day and every completed lap or measured distance counts.
200+ Mile Races
A continuous fixed-distance ultramarathon where route, terrain, sleep, aid access, and a multi-day cutoff shape the race.