Originally written June 22, 2026
Updated July 17, 2026
By Ken Hamada, Race Director
Introduction
Putting on the 2026 race has been extremely difficult because of two major challenges:
- The aftermath of the 2025 Eaton Fire, which closed the Idlehour Trail.
- Highway 2 closures caused by this year’s winter storms.
Course Challenges
In 2025, we had to deal with the aftermath of two major fires in the Angeles National Forest.
The Bridge Fire started in September 2024 and burned more than 50,000 acres in the Wrightwood area, causing the evacuation of the entire community.
The Eaton Fire started in January 2025 near Altadena. It burned for 24 days, consumed approximately 14,000 acres, destroyed 9,400 structures—mostly homes—and took 19 lives.
Many of the trails from Idlehour to Sam Merrill were heavily damaged. The Eaton Fire first burned the trees and ground cover, and the following winter storms and rain further eroded the trails. Fortunately, the mountain bike club Lowe Life has been completing major repair work on the Idlehour Trail, and it may be ready for use by 2027.
Highway 2 Closures
Highway 2 was damaged by this year’s heavy winter storms in two locations:
- Between Islip Saddle and Vincent Gap, near Islip Saddle.
- In front of the Mt Waterman Ski Area.
These conditions resulted in Highway 2 closures at Islip Saddle, Big Pines, and near Cloudburst.
In the past, when Highway 2 was closed between Islip Saddle and Vincent Gap, we could adjust and still hold a point-to-point race. This year, however, the additional closure near the Mt Waterman Ski Area made it impossible to operate aid stations between Inspiration Point and Cloudburst.
We have always started the race in Wrightwood, even when using an out-and-back course. The closure near Mt Waterman has made that impossible for 2026, so this year’s race will start and finish at Loma Alta Park in Altadena.
The 2026 Course
The Idlehour Trail is within the Eaton Fire Closure Area, so we needed to find a way to avoid that section while still finishing at Loma Alta Park.
Fortunately, Travis Metzger found a route that allows runners to pass through the Mueller Tunnel at Eaton Saddle, use the paved road between Red Box and Mt Wilson, and then follow the Mount Lowe Motorway. This route avoids the Eaton Fire Closure Area before passing through the Sam Merrill Aid Station and following the Sunset Trail at the Cape of Good Hope to Millard and Loma Alta Park.
The new 2026 AC100 course will begin on the streets of Altadena and use the Gabrielino Trail. The course will pass through:
- Switzer Picnic Area
- Clear Creek Aid Station
- Josephine Saddle
- Josephine Peak Aid Station
- Red Box
- Newcomb
- Chantry Flats
- Mt Wilson
- Eaton Saddle and Mueller Tunnel
- Sam Merrill
- Millard
- Loma Alta Park
Josephine Peak will serve as an aid station for the first time. Chantry Flats, which had been closed for several years because of damage from the Bobcat Fire, has been repaired and reopened.
Race Preparations
Major course-clearing work was completed in April and May. Additional trail workdays have been scheduled to prepare the course for race day.
All aid stations have been assigned leaders. In the months ahead, I will work with those leaders to address any issues they may have, especially those related to the new course.
For upcoming trail work dates and volunteer information, visit the Trail Work page.
The 2026 course map, elevation profile, and checkpoint cutoff table have been updated. View the 2026 Checkpoint Cutoffs.
Looking Ahead
During the race’s first 20 years, beginning in 1986, the AC100 was never canceled. Remarkably, we did not encounter a forest fire or a winter storm-related Highway 2 closure that prevented us from holding the race.
Over the last 20 years, we have faced several major forest fires, including the Station Fire, Bobcat Fire, Bridge Fire, and Eaton Fire. The COVID-19 pandemic, together with the Bobcat Fire, caused the race to be canceled in 2020 and 2021.
We have also dealt with frequent Highway 2 closures between Vincent Gap and Islip Saddle. In previous years, we found ways to work around those closures and maintain a point-to-point race. This year, the closures between Vincent Gap and Islip Saddle and near the Mt Waterman Ski Area made it impossible to operate aid stations between Inspiration Point and Cloudburst.
Here’s hoping for a better next 20 years!