Quicksilver Endurance Runs, live.

Hill after hill in the old quicksilver mines

The 2027 Quicksilver 100K and 50K are on Saturday 8 May 2027 in Almaden Quicksilver County Park, on the south side of San Jose, California.

The Quicksilver Endurance Runs are put on by the Quicksilver Running Club of San Jose, a non profit club, with the help of more than 100 volunteers every year. Both races are USA Track and Field sanctioned, and the 100K is part of the USATF Pacific Mountain Ultra Trail Grand Prix.

The 100K starts at 4:30 am from the Hacienda entrance of the park, so a light is required at the start. Runners can leave their headlamp at the Wood Road aid station and collect it at the finish. The course measures 62 miles with more than 13,000 feet of gain and a 17 hour limit, and every official finisher qualifies for the Western States 100 lottery.

The 50K starts at 7:00 am and covers 30.3 miles with more than 6,000 feet of gain. Its cutoff is 4:30 pm at mile 22. The organiser publishes a printable one page guide for each race with the aid station chart, cutoffs and map, plus turn by turn directions and GPX files.

Registration opens on Saturday 14 November 2026 at midnight Pacific time. On race day the organiser asks volunteers to cover everything from bib pickup and parking to aid stations, sweeps and course marking, so friends who come along can also help out.

On Livebib you can follow a participant who chooses to share their own live position from the phone they carry. This is not the organiser's timing, and official results come from the Quicksilver Running Club.