The field atlas of American ultramarathons

Find your next hundred.

255 hundred-mile races, mapped and dated — so the only thing left to figure out is whether you can finish.

Browse the mapSee the calendar
255
Hundred-mile races
49
States covered
51
Western States qualifiers
17
Hardrock qualifiers

Next on the calendar

On the horizon

The soonest confirmed starts — the ones worth building a season around.

JUN13'26

Cool Moon

Cool, CA

▲ 16,000 ftLoop
JUN13'26

Kettle Moraine

WS

La Grange, WI

▲ 11,000 ftOut & back
JUN19'26

Bighorn

WS

Dayton, WY

▲ 19,000 ftOut & back
JUN19'26

Burney Mountain

Burney, CA

▲ 12,000 ftLoop
JUN20'26

Ring the Springs

Colorado Springs, CO

▲ 16,000 ftLoop
JUN20'26

Strawberry Fields Forever

North Bonneville, WA

▲ 3,200 ftLoop
See the full calendar →

◈ From the runners

Rate the races you’ve finished.

Ratings and trip reports are open to everyone while the atlas fills in. Find a race you’ve finished and add a finisher’s report — the kind of detail the race website won’t tell you.

  • Six dimensions

    Rate course, scenery, aid stations, organization, difficulty, and vibes — not one blunt star.

  • Trip reports

    Read the long-form accounts: where it broke people, what they wish they'd known.

  • Real voices only

    One account, one voice. Every rating is signed by a runner — no bot brigades, no review farms.