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.

JUL31'26

Lean Horse

Custer, SD

▲ 5,000 ftOut & back
AUG1'26

Badger

Belleville, WI

▲ 2,000 ftOut & back
AUG1'26

Hood Hundred

Mt Hood Meadows, OR

▲ 17,000 ftOut & back
AUG7'26

High Five

Lake City, CO

▲ 38,000 ftLoop
AUG7'26

Wyoming Range

HR

Big Piney, WY

▲ 22,000 ftPoint to pointLottery
AUG8'26

Eastern States

WS

Waterville, PA

▲ 21,000 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.