Calero Run 50K

Race completed

50 km Distance

1,600 m Climbing

4.9 Grit · Challenging

37.3394° N, 121.8950° W© OpenFreeMap © OpenMapTiles Data from OpenStreetMap

What the course asks

Climbing rate 32 m / km Rolling. Moderate undulations. Requires consistent effort across varying grades.

Time limit 12 hours 14:24 min/km average. Generous. Walkable throughout for most of the field. More forgiving than 70% of 50K races. Measured against 1007 races of the same distance. Cut-off calculator →

Field size ~1 Tiny. You will run alone for most of it.

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, May

Daytime high 21°C

Night low 8°C

Rainfall Dry — rain unlikely

Daylight 14 h 31 m of light

Regional 2001-2020 average for May — NASA POWER, grid elevation 233 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 1,600 m of ascent.

Trail Running Shoes32 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 Poles1,600 m of ascent to walk up.
HeadlampsA 12 h limit puts you out there after dark.

Adidas

Terrex Agravic Speed Ultra

★★★★★ 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

Spring Energy