San Jose, CA, United States · Saturday, December 5, 2026

Fixed Distance 50K

Calero Park Run 50K

47 days away

50 km Distance

not publishedn/a Climbing

2.5 est Grit · Entry level

Calculated from 50 km alone — the organiser has not published an elevation profile. Read 2.5 as a floor, not a verdict.

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

What the course asks

Time limit 9 hours 10:48 min/km average. Firm. Climbing is unpublished, so this pace is a ceiling on the effort, not a measure of it. About average for a 50K. Measured against 1058 races of the same distance. Cut-off calculator →

Field size ~19 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, December

Daytime high 13°C

Night low 4°C

Rainfall Showers likely

Daylight 9 h 44 m of light

Regional 2001-2020 average for December — NASA POWER, grid elevation 233 m. Not a forecast.

Results history

Year	Race	Finishers	Men's winner	Women's winner
2025	50km	19	Oliver Kaard · 04:06:12	Zoe Bell · 06:23:11
2024	50km	13	Jonathon Hazell · 04:32:54	Jeannie Munoz · 07:23:23
2023	50km	14	Stephen Sims · 05:59:56	Angelica Lerro · 06:17:21
2022	50km	11	Kermit Cuff · 06:11:18	Olivia Srednicka · 06:55:01
2021	50km	8	Kermit Cuff · 05:43:13	Katie Hawn · 05:27:43
2019	50km	13	Clement Guillaume · 04:51:43	Katie Skuratovskiy · 06:13:30
2017	50km	4	Kermit Cuff · 05:25:17	—
2016	50km	3	Eric Aldrich · 04:57:30	—

The field grew 46% between 2024 (13) and 2025 (19). 21% of the 2025 field were women.

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.

Course notes

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

Gear for this race

Chosen for 50 km of trail.

Trail Running Shoes 50 km of trail — cushioning that is still there in the last quarter.
Race Nutrition 50 km of self-supported fuelling between aid stations.
Hydration Vests Flask capacity for 50 km, without the bounce.
GPS Watches Battery life first — a 50 km day outlasts most full-GPS modes.

Adidas

Terrex Speed Ultra

RunRepeat found the Adidas Terrex Speed Ultra to have a grippy outsole and great lockdown, while iRunFar noted that the shoe works on a variety of trail conditi…

★★★★★ 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

Nathan

VaporKrar 12L

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

$170 ★★★★★ 4.6

Suunto

Vertical

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

$630 ★★★★★ 4.5

All gear guides →

Overview

The Calero Park Run 50K in San Jose, CA is scheduled for December 5, 2026. This trail race features a 50-kilometer course.

The time limit of 9 hours means this race has a cut-off tighter than 65% of 50k races, corresponding to a maximum pace of 10.8 minutes per kilometer. With 8 past editions, the last in 2025, this 50k has seen a maximum of 19 finishers in its most recent running. The field size is bigger than 30% of 50k fields and smaller than 69%.

Similar races

Other 50K trail ultras, closest in distance first.