Ultra Running Hub Stillwater, OK, United States · Saturday, November 21, 2026
Fixed Distance 50 mi
40/50 Mile Challenge - Lake Carl Blackwell
66 days away
80 km Distance
not publishedn/a Climbing
4.0 est Grit · Challenging
Calculated from 80 km alone — the organiser has not published an elevation profile. Read 4.0 as a floor, not a verdict.
What the course asks
Time limit 12 hours
9:00 min/km average. Comfortable. Room to walk the climbs and stop at aid. Climbing is unpublished, so this pace is a ceiling on the effort, not a measure of it. Among the tightest 50 mi cut-offs we track. Measured against 455 races of the same distance. Cut-off calculator →
Typical conditions, November
Daytime high 16°C
Night low 3°C
Rainfall Mostly dry
Daylight 10 h 08 m of light
Regional 2001-2020 average for November — NASA POWER, grid elevation 287 m. Not a forecast.
The Aid Station
Course-specific beta from the community
With trail terrain, choose a shoe with moderate cushioning for optimal performance.
Gear for this race
Chosen for 80 km of trail.
- Trail Running Shoes80 km of trail — cushioning that is still there in the last quarter.
- Race Nutrition80 km of self-supported fuelling between aid stations.
- Hydration VestsFlask capacity for 80 km, without the bounce.
- HeadlampsA 12 h limit puts you out there after dark.
- GPS WatchesBattery life first — a 80 km day outlasts most full-GPS modes.
Course Notes
Lake Carl Blackwell (11000 W Hwy 51), Stillwater OK. A 3.1-mi (5K) loop repeated to 40 or 50 miles, back to a central start/finish and stocked aid each lap. Surface: dirt, grass, lightly packed earth. Rolling lakeside terrain, grassland, woods.
Similar races
Other 50 mi trail ultras, closest in distance first.