Skyline 50k Endurance Run

Castro Valley, United States • 2 Aug 2026

Event Information

The Skyline 50k Endurance Run is an ultramarathon held each August. It is described as one of the oldest continuously running 50 km races in the United States and the longest-running one in California. The route is a large loop starting and finishing at Lake Chabot Marina in Castro Valley, traveling through the East Bay Regional Parks to Skyline Gate.

Race Details

Two distances are offered:

  • 50 km
  • Half Marathon

The event features aid station support provided by local running groups. A Volunteer Safety Patrol is present at key intersections. After the race, a plant-based BBQ and beer are provided for participants. Families are welcome. All runners receive a race shirt, Skyline socks, and a finisher's medal. Awards are given to overall winners and age group placers.

Registration and Logistics

Bib pickup is available the day before the race in Berkeley or on race morning at Lake Chabot Marina. The 50k is part of the P-USATF Grand Prix and is a UTMB Index event. Full athlete guides with course maps and aid station details are available for download. Visit the organization's website for the most recent information.

Race information

UTMB 50K
50 km
Skyline 50k
Visit the organization's website for the most recent information.
Trail runs nearby

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Montara Mountain Trail Run in Pacifica on Feb 21, 2026 offers distances from a 10K to a 50K plus a free kids 50 yd dash, marked courses, aid stations every 6 to 7 miles, and a cupless hydration policy.

This trail run in Walnut Creek's Lime Ridge area features unmapped courses. Runners follow a map to find checkpoints, choosing their own path through oak trees and quarries. Snacks await at the finish.

The Zoom Angel Island will take place in Tiburon on Sunday 1 March 2026. You can run between 5 and 15 miles.