BestRacesEditor’s note, September 23, 2026: The index this drew on held 4,965 races; it now holds 7,000. On September 22 we found that RunSignup’s race search returns races in alphabetical order and stops at 5,000 results, so every race we had ever synced was named with a number or a letter from A to F. Searching state by state found 16,101 upcoming US races. The ten below are unchanged and two still clear our scoring floor, but the hundred-mile list is no longer complete: the Star of Louisiana 100 in Keithville and the Sangre de Cristo Trail Festival in Westcliffe, Colorado both start a hundred miles on foot and both arrived with the new races. We have not restated the count, because most listings that mention 100 miles are virtual mileage challenges, relay legs or bike centuries rather than one runner starting one race, and separating them is a judgment we make by hand.
Our index holds 4,965 races. Ten of them will let you start a hundred miles on foot. That count is accurate. It is the actual size of the American hundred-mile calendar as it reaches us, and it is worth staring at before you start planning a year around one.
The ten
| Race | Date | Location | Surface | Score |
|---|---|---|---|---|
| Leadville Trail 100 | Aug 22, 2026 | Leadville, CO | trail | 70.4 |
| Quantico 24-Hour | Oct 3, 2026 | Quantico, VA | road | 15.0 |
| Cactus Rose | Oct 23, 2026 | Bandera, TX | trail | 20.0 |
| Colorado River Run | Nov 27, 2026 | Cedar Creek, TX | trail | 20.0 |
| Brazos Bend 100 | Dec 5, 2026 | Needville, TX | trail | 20.0 |
| Crooked Creek | Dec 5, 2026 | Shepherdsville, KY | trail | 20.0 |
| Ancient Oaks 100 | Dec 19, 2026 | Titusville, FL | trail | 20.0 |
| Blackbeard’s Revenge 100 | Mar 20, 2027 | Corolla, NC | road | 15.0 |
| Dawn to Dusk to Dawn | May 8, 2027 | Sharon Hill, PA | road | 15.0 |
| Western States 100 | Jun 26, 2027 | Olympic Valley, CA | trail | 72.2 |
Leadville’s 2026 edition ran on August 22; every other race on that list is still ahead of you.
Two of the ten score above our floor. Western States (72.2) was founded in 1974, takes 370 starters over 18,000 feet of Sierra climb, and posts a perfect 100 for both longevity and character. Leadville (70.4) started in 1983 and runs 700 people out and back above 10,000 feet. The other eight sit on the floor for the same reason 3,541 fall races did in our last count: no published field size, no founding year, no certification on record. Eight of these ten races have none of the three. That is a gap in the documentation rather than a judgment on the races, and in the ultra world it is close to normal, because the sanctioning machinery built for road racing was never pointed at a 30-hour footrace.
Four of them run in the dark half of the year
Colorado River Run, Brazos Bend, Crooked Creek, and Ancient Oaks all fall between November 27 and December 19, past the equinox, when night is longer than day everywhere in the country. Even the June and August races put you out there overnight: unless you can cover a hundred miles in under fifteen hours, and almost nobody can, you will run in the dark. Every one of these races knows it, which is why the kit list exists at all.
To see which mile that happens at, put a goal time into the pacing plan on the Western States page. It lists your elapsed time at every mile to the finish and tells you what the course’s 18,000 feet of climbing is worth. It’s free, with nothing to sign up for.
What the list converges on
Each race publishes its own required-gear list, and that list is the binding one. Read it before you read anyone’s advice, including ours. But across the sport the mandatory column converges on three things, and all three are consequences of that overnight math rather than anyone’s preference.
Light, and a second light. A headlamp is standard at gear check. A backup is standard too, because the failure mode of one dead lamp at mile 71 is a runner sitting on a rock waiting for company.
Your own water between aid stations. This is the item first-timers get wrong. Seven of the ten are trail races, and on trail the gap between aid can be an hour or more of climbing, so races specify a carrying capacity rather than a bottle. A running hydration vest is the usual answer, and it is worth buying early: it is the one piece of kit you must train in for months, because a vest that fits at mile 6 and not at mile 60 is the difference between a finish and a DNF.
A layer you did not want to bring. Overnight in the Sierra or the Rockies is a different climate than the same course at noon, and the required jacket is on the list precisely because nobody carries one voluntarily.
Start shorter
Thirty-six races in our index offer a 50K or a 50-miler, and three clear the floor: the JFK 50 (65.2, founded 1963, a field of ~1,200, and the oldest ultra in America), Chuckanut 50K (59.3), and Quad Rock 50 (54.2). All three sit in the trail rankings, and all three will teach you whether your vest fits before a hundred miles asks the question for you.
As an Amazon Associate we earn from qualifying purchases. Gear links never affect which races we cover or how they rank.