Welcome to the premier 100 mile running event in San Diego

Scenic & Challenging 100 Miles in Mt Laguna Recreational Area and along the Pacific Crest, Noble Canyon, and Lake Cuyamaca Trails. This is the 16th annual event.


Where: Lake Cuyamaca, California, USA
Race Day Runner Tracking: Ultralive
New: Friday Start at 6:00am: (6/8/2018)
Registration: Ultrasignup

2018 (17th) RACE STARTS IN:

2018-6-8 6:0:0 GMT-07:00
June 8, 2018 6:00:00 AM/PST


Qualification requirements to enter the 2018 event are as follows: Applicants must have completed an official 50 mile race in less than 13 hours from between January 1,2016 through April 15, 2018. Anyone who has completed an official 100K or 100 mile run in the last 2 years (January 1, 2016 to April 15, 2018 is also qualified to apply.

We'll accept applications on Ultrasignup beginning 1/1/2018 through the deadline of midnight of 1/4/2018. A lottery will take place if over 300 qualified applications are received. If there are less than 300 applicants, entries will reopen on ultrasignup until the 300 person limit is reached. A waitlist will be maintained on Ultrasignup once the field limit of 300 is reached. The latest date for wait listed applicants to receive a slot is April 15, 2018. After that date, there will be no refunds for entrants and no other applicants will be accepted.

All entrants are required to perform 6 hours of volunteer work within a year prior to the start of the 2018 race as a requisite to participate. We expect entrants to attempt to accomplish their volunteer work on trail maintenance but volunteering at an ultra or other race, or by volunteering at a community service is acceptable.

The start and finish line are at Lake Cuyamaca which is located at 15207 Highway 79 near Julian, CA. The Lake Cuyamaca web site (with information about camping and RV reservations) is located at: Lake Cuyamaca Website. Also check out additional lodging options under this web site's Event Info link to Accommodations.

Questions not covered on the race website can be directed to: scottemills51@gmail.com


Sales for a 2019 free entry to San Diego 100 and numerous other Sponsor Giveaway Gifts to be selected at this year's pre-race briefing. Proceeds support San Diego Trailfit. Raffle tickets are $5 each or 5 tickets for $20.

Our Sponsors

  • Altra Running Footwear
  • Black Diamond
  • Clif Bar
  • Dirty Girl Gaiters
  • Foot Kinetics
  • High Desert Drop Bags
  • Injinji
  • Julbo Eyewear
  • Movin Shoes
  • Orangemud
  • Patagonia
  • Pulse
  • Running Skirts
  • SD Ultra Running Friends (SURF)
  • SoCal Ultra Series
  • Squirrel's Nut Butter
  • Tailwind Nutrition
  • Ultra Running Magazine
  • Ultra Trail Du Mont Blanc
  • Ultralive.Net
  • Western States
Race Pictures By:
Howie Stern Photos
© 2018 San Diego 100