Trail half marathons in California, United States
Find trail half marathons in California, United States. Compare 20 upcoming events by date and location. Open a race guide for the course, recorded editions and official entry information where available.
Events to explore include No Name Trail Races, Trail Run at Sly Park - Fall and Griffith Park Trail Races.
21 listed events · 20 with upcoming dates
Upcoming half marathons
20 matching events, earliest date first. Entry availability is shown separately.
No Name Trail Races
USAAgoura, California
Trail races through Cheeseboro Canyon in the Santa Monica Mountains, with an ultra, half marathon and shorter course.
· Half marathon
Race details, entry and past editions →Entry information ↗Trail Run at Sly Park - Fall
USAPollock Pines, California
Autumn trail races around Jenkinson Lake at Sly Park Recreation Area.
· Half marathon
Race details, entry and past editions →Entry information ↗Griffith Park Trail Races
USALos Angeles, California
Hilly trail races on Griffith Park’s singletrack and fire roads, starting at the Merry-Go-Round parking area.
· Half marathon
Race details, entry and past editions →Entry information ↗Calero Trail Run Winter
USASan Jose, California
Winter trail races on Calero County Park’s singletrack and rolling dirt paths, with several distances from one mile to an ultra.
· Half marathon
Race details, entry and past editions →Entry information ↗Doomsday
USACool, California
Trail races from the Cool Staging Area, with a 50K ultra and half marathon through the surrounding foothills.
· Half marathon
Race details, entry and past editions →Entry information ↗Woodside Ramble
USAWoodside, California
Trail races through the redwood forest and hills of Huddart County Park.
· Half marathon
Race details, entry and past editions →Entry information ↗Dirty December Trail Run
USASan Diego, California
Holiday trail races at Sycamore Canyon, with three fixed distances and a timed hill-climb challenge.
· Half marathon
Race details, entry and past editions →Entry information ↗Brazen New Year’s Day
USACastro Valley, California
New Year’s Day trail races around Lake Chabot in Castro Valley.
· Half marathon · Status TBC
Race details, entry and past editions →Hacienda Hills Trail Run – Winter
USASan Jose, California
Winter trail races through the hills of Almaden Quicksilver County Park.
· Half marathon
Race details, entry and past editions →Entry information ↗Crystal Springs Winter Trail Run
USAWoodside, California
Winter trail races through Huddart Park and the coastal redwoods.
· Half marathon
Race details, entry and past editions →Entry information ↗Folsom Lake Sweetwater Trail Run
USAEl Dorado Hills, California
Trail races beside Folsom Lake, mainly on singletrack with some dirt road.
· Half marathon
Race details, entry and past editions →Entry information ↗Del Dios Trail Race
USAEscondido, California
Trail races around Lake Hodges, with singletrack and dirt service roads.
· Half marathon
Race details, entry and past editions →Entry information ↗Sycamore Canyon Ultras
USAPoway, California
Looped trail ultras and a half marathon at Sycamore Canyon Preserve.
· Half marathon
Race details, entry and past editions →Entry information ↗Redwood (Spring) Trail Run
USAOakland, California
Trail races through Redwood Regional Park with redwood groves and ridge views.
· Half marathon
Race details, entry and past editions →Entry information ↗VALENCIA Trail Race
USAValencia, California
Hilly trail races on ridges and through canyons above the Santa Clarita Valley.
· Half marathon
Race details, entry and past editions →Entry information ↗Grizzly Peak Trail Run
USABerkeley, California
Trail races through the wooded hills of Tilden Regional Park.
· Half marathon
Race details, entry and past editions →Entry information ↗Cinderella Trail Run
USAOakland, California
Trail races through Joaquin Miller and Redwood Regional parks.
· Half marathon
Race details, entry and past editions →Entry information ↗Malibu Canyon Trail Races
USAMalibu, California
Trail ultras and shorter races in Point Mugu State Park.
· Half marathon · Status TBC
Race details, entry and past editions →San Lorenzo River Trail Run
USASanta Cruz, California
Trail races through redwood forests and across the San Lorenzo River.
· Half marathon
Race details, entry and past editions →Entry information ↗Redwood Summer Trail Run
USAOakland, California
Trail races through Redwood Regional Park with a short children’s dash.
· Half marathon
Race details, entry and past editions →Entry information ↗Race archive
Past races and previous editions
Looking back at a race? Browse the guides below for recorded editions. This section also includes events awaiting a new date and cancelled editions. Previous editions of races in the upcoming calendar are available through their race guides above.
CTR Diablo Trail Run
USAClayton, California
CTR Diablo Trail Run in Clayton.
Next date not listed
Race guide and recorded editions →Choosing a race in California
The unfiltered upcoming calendar includes events in Oakland (3), San Jose (2), Woodside (2). Use the town filter to compare locations, then check the race guide for the start venue and organiser’s travel information.
Questions about half marathons in California
Which trail half marathons are coming up in California, United States?
No Name Trail Races is listed for 24 October 2026. Trail Run at Sly Park - Fall is listed for 24 October 2026. Griffith Park Trail Races is listed for 21 November 2026. Check the race guide and organiser’s latest information before making plans.
Where can I find race entry details for California, United States?
Follow the link from the race guide to the organiser or entry provider, where one is available. Check the entry deadline, eligibility and current availability there. A listed race date does not necessarily mean entries are still open.
Why has a race moved out of the upcoming calendar?
Once its listed dates have passed, a race moves to the past-editions view unless another upcoming edition is recorded. Cancelled events also leave the upcoming list. The race guide stays available, and the event returns when a new date is added.