BestRacesOur index holds 6,840 running races. 407 of them, about 6%, are trail races, meaning their listings describe a trail course. Small as that share is, it holds most of the long stuff. Of the 95 listings that offer a standard ultra distance (50K, 50 miles, 100K, 100 miles and up), 58 are on trail. That is 61% of the ultras from 6% of the races.
So a first trail race is often a first long race too. Either way, it changes the job in ways a road résumé doesn’t prepare you for. Here is what the numbers say, and what they mean on race day.
The climbing is a different sport
We have measured elevation gain for eight trail races, the curated ones at the top of our trail rankings. Set against the Boston Marathon, a famously hilly road course, here is the climbing per mile:
| Race | Distance | Gain (ft) | Per mile |
|---|---|---|---|
| Boston Marathon (road) | Marathon | 810 | 31 |
| JFK 50 Mile | 50 miles | 3,000 | 60 |
| Black Canyon 100K | 100K | 5,800 | 93 |
| Leadville Trail 100 | 100 miles | 15,600 | 156 |
| Chuckanut 50K | 50K | 5,000 | 161 |
| Western States 100 | 100 miles | 18,000 | 180 |
| Quad Rock 50 | 50 miles | 11,000 | 220 |
| Dipsea Race | 7.4 miles | 2,200 | 297 |
| Broken Arrow Skyrace | 46K | 9,800 | 343 |
The gentlest course here climbs at nearly twice Boston’s rate. The steepest climbs at 11 times it. On that kind of ground your road pace means very little. Experienced trail runners race by effort, not the watch, and walking the steep climbs is standard practice, not a failure. Plan to finish slower than a road race of the same length, and judge your race against your effort, not the clock.
You can see what that climbing looks like before you sign up. Here is a 3D flyover of the Black Canyon 100K: press “Fly the course” and the camera follows the route over the terrain.
The distance is approximate
Of 6,433 road races in our index, 439 have a USATF-certified course. Of the 407 trail races, none do, and none is a Boston qualifier. That is not a mark against them. Certification measures a course along the shortest possible line, a method built for roads. On singletrack, a 50K may run long or short, and the course can change from year to year with trail closures or reroutes. Our ranking engine scores trail races on their own curve for exactly this reason: it doesn’t mark them down on credentials they can’t earn.
For you, that means trail times don’t compare the way road times do, even at the same race. A PR on a course that moved is not a PR.
The fields are small and the start matters
Among the 197 trail races with a published field size, the median is 93 runners; on road it is 143. More than half of those trail races (104 of 197) finish fewer than 100 runners. Only two top 1,000: the Dipsea Race (1,395) and the JFK 50 Mile (1,111).
A small field on a narrow trail means single file, often within the first mile. Pick your starting spot honestly. If you start too far forward, you will be holding up a line of runners on the first climb. If you start too far back, you can spend a mile stuck behind slower runners. Call out before you pass (“on your left”), and step aside for faster runners when the trail allows.
You carry more of the race yourself
Road marathons put water every mile or two. On trail, aid stations can be many miles apart, and many trail races ask runners to carry their own cup. Course marking means flags and ribbons rather than barricades and volunteers at every turn, so a missed turn is your problem. The usual fixes: carry water between aid stations, learn the marking scheme at the pre-race briefing, and know the cutoff times before you start.
The biggest single change is underfoot. Road shoes are built for grip on pavement. On mud, roots and loose rock, a pair of trail running shoes with a lugged outsole is the one piece of kit most trail runners would put first.
Where to start
The index lists 245 upcoming trail races across 47 states. Texas has the most (30), then Ohio (26), Pennsylvania (24), Colorado and Connecticut (23 each). It is peak season: 128 of the 245 are in October or November. Most are short. Among the trail races in our index, 185 offer a 5K and 90 offer a 10K, which is the best way to find out whether you like the dirt before signing up for anything long.
Sixteen trail races have enough measured data to rank. The other 391 lack the measured signals they need. If you direct one of them, claiming your listing is free. It can’t buy a better rank, only a more complete one.
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