What Is the San Diego 100 Course Like?

Updated

The San Diego 100 is a 100-mile endurance race run in the Mt Laguna Recreational Area and along the Pacific Crest, Noble Canyon, and Lake Cuyamaca trails. The race's own description calls it scenic and challenging, and an "Old School Favorite." The 25th annual event is scheduled to begin Friday, April 30, 2027, at 0600.

Where the Course Runs

According to the race website, the route covers 100 miles through the Mt Laguna Recreational Area in San Diego County's backcountry, using three named trail systems:

  • Pacific Crest Trail — the long-distance National Scenic Trail that passes through the Laguna Mountains
  • Noble Canyon Trail — a well-known San Diego-area trail in the Cleveland National Forest
  • Lake Cuyamaca trails — paths around and near Lake Cuyamaca

The mix of mountain terrain and these specific trails is what the race points to when it describes the course as both scenic and challenging.

What That Means for Runners

The description gives you the setting and the trail systems, but not a mile-by-mile profile, elevation chart, or aid station list. For those specifics, the race directs runners to the 2027 Racebook, which the site says will be posted with more details.

One practical detail that does appear in the race information: runners over 60 may start one hour early. However, aid stations open at their usual times, so anyone using the early start should be prepared to self-support until the Cuyamaca Peak aid station.

Course-Related Context for 2027

  • The 2026 San Diego 100 was selected as a qualifying race for the 2027 Western States 100. Finishing within 32 hours qualifies a runner for the Western States lottery.
  • The qualifying period for the 2027 Western States runs from November 4, 2025, through November 2, 2026, with the lottery on December 6, 2026, and the race on June 26–27, 2027.
  • Registration for the 2027 San Diego 100 opens January 1 at 12:01 AM, first-come, first-served.

What the Course Description Does Not Cover

The available race information does not include elevation gain, cutoff times by segment, crew access points, or a detailed course map. If you are deciding whether to enter, treat the "scenic and challenging" framing as a general signal about the terrain rather than a substitute for the Racebook. The Racebook, when posted, is the source to check for the specifics that affect pacing, drop bags, and crew logistics.

For questions, the race lists its contact as [email protected], and registration runs through UltraSignup.