Mt. Wilson, CA, United States · Saturday, September 26, 2026

Fixed Distance 50K

Mount Disappointment Mountain Race

10 days to go

50 km Distance

1,740 m Climbing

5.1 Grit · Challenging

34.2239° N, 118.0612° W© OpenFreeMap © OpenMapTiles Data from OpenStreetMap

What the course asks

Climbing rate 35 m / km Rolling. Moderate undulations. Requires consistent effort across varying grades.

Time limit 10 hours 12:00 min/km average. Generous. Walkable throughout for most of the field. About average for a 50K. Measured against 1007 races of the same distance. Cut-off calculator →

Field size ~39 Small. Long stretches with nobody in sight.

DUV results for the 2025 edition (50km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.

Typical conditions, September

Daytime high 29°C

Night low 17°C

Rainfall Dry — rain unlikely

Daylight 12 h 03 m of light

Regional 2001-2020 average for September — NASA POWER, grid elevation 395 m. Not a forecast.

The Aid Station

Course-specific beta from the community

⛰️ terrain

This is a rolling course. Expect fast, runnable sections where rhythm is key.

By UltraHub Expert

👟 gear

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

By UltraHub Expert

Gear for this race

Chosen for 50 km of trail with 1,740 m of ascent.

Trail Running Shoes35 m of climb per kilometre — grip and rock protection before cushioning.
Race Nutrition50 km of self-supported fuelling between aid stations.
Hydration VestsPole attachment and chest-strap stability on steep ground.
Trekking Poles1,740 m of ascent to walk up.
GPS WatchesBattery life first — a 50 km day outlasts most full-GPS modes.

Adidas

Terrex Speed Ultra

★★★★★ 4.5

Salomon

Sense Ride 5

RunRepeat found the Salomon Sense Ride 5 to have immaculate lockdown and a smooth and stable ride, making it confident on moderate trails and steep downhills. I…

★★★★★ 4.5

Skratch Labs

Sport Hydration Mix

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

$20 ★★★★★ 4.5

Salomon

ADV Skin 12

Industry-standard 12L race vest with front flask pockets and minimal bounce.

$180 ★★★★★ 4.8

Komperdell

Carbon Ultralight Vario 4

4-section folding carbon poles with compact pack size for mandatory gear.

$160 ★★★★★ 4.5

Suunto

Vertical

Titanium GPS watch with solar charging, offline maps, and 140-hour GPS battery.

$630 ★★★★★ 4.5

All gear guides →

Course Notes

Start at the summit of Mt. Wilson (Mt. Wilson Observatory parking lot).Course is scenic, yet strenuous and challenging. Final climb to the summit of Mt Wilson up the Kenyon Devore Trail.

Similar races

Other 50K trail ultras, closest in distance first.