Middleville, MI, United States · Friday, May 29, 2026

Fixed Distance 100K

Yankee Springs 100 km Trail Run

Race completed

100 km Distance

not publishedn/a Climbing

5.0 est Grit · Challenging

Calculated from 100 km alone — the organiser has not published an elevation profile. Read 5.0 as a floor, not a verdict.

42.7131° N, 85.4620° W© OpenFreeMap © OpenMapTiles Data from OpenStreetMap

What the course asks

Time limit 18 hours 10:48 min/km average. Generous. Walkable throughout for most of the field. Climbing is unpublished, so this pace is a ceiling on the effort, not a measure of it. About average for a 100K. Measured against 208 races of the same distance. Cut-off calculator →

Field size ~8 Tiny. You will run alone for most of it.

DUV results for the 2026 edition (100km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.

Typical conditions, May

Daytime high 20°C

Night low 8°C

Rainfall Showers likely

Daylight 15 h 01 m of light

Regional 2001-2020 average for May — NASA POWER, grid elevation 247 m. Not a forecast.

The Aid Station

Course-specific beta from the community

👟 gear

With trail terrain, choose a shoe with moderate cushioning for optimal performance.

By UltraHub Expert

🥤 nutrition

For 100km+ efforts, prioritize real food at aid stations to prevent palate fatigue.

By UltraHub Expert

Gear for this race

Chosen for 100 km of trail.

Trail Running Shoes100 km of trail — cushioning that is still there in the last quarter.
Race NutritionPast 100 km the palate quits before the legs do — carry more than one flavour.
Hydration VestsFlask capacity for 100 km, without the bounce.
HeadlampsA 18 h limit puts you out there after dark.
AccessoriesChafe and blisters end more 100 km races than fitness does.

Salomon

Aero Glide 4 Grvl

$159.95 ★★★★★ 4.5

Brooks

Catamount 3

RunRepeat found the Brooks Catamount 3 to have a cozier upper that enhances the overall fit, though breathability and durability could be better. iRunFar noted…

★★★★★ 4.5

Skratch Labs

Sport Hydration Mix

Clean electrolyte drink mix with real fruit flavor. Low sugar.

$20 ★★★★★ 4.5

Nathan

VaporKrar 12L

12L race vest co-designed with ultra champion Rob Krar, with insulated bladder pocket.

$170 ★★★★★ 4.6

Petzl

NAO RL

1500-lumen reactive lighting headlamp with 15-hour runtime. Automatic brightness adjustment.

$150 ★★★★★ 4.7

Buff

CoolNet UV+ Multifunctional

UPF 50+ neck gaiter with cooling technology. Desert and sun essential.

$25 ★★★★★ 4.5

All gear guides →

Course Notes

The courses are 100% single track trail through the woods of the Yankee Springs Recreation Area. The terrain features hills and valleys carved by glaciers as well as a fair amount of rocks and roots to dance around.

Similar races

Other 100K trail ultras, closest in distance first.