San Gabriel Marathon Loop

The San Gabriel Marathon Loop is a 26.4-mile loop in the San Gabriel Mountains outside the town of Altadena. It connects the Gabrielino Trail, Disappointment Ridge and San Gabriel Peak Trail, Mt. Lowe Road, Millard Canyon, and El Prieto Canyon. This loop has a few potential starting locations: Millard Falls Trailhead, Switzer Falls Trailhead, or Red Box Picnic Area. This route is made difficult not only due to its mileage and exposure, but also due to significant elevation gain and loss as it navigates the range. These ascents and descents are long, steep and relentless, but the rewards are many. To make this into an overnight trip, one can plan to camp at Millard Trail Camp and/or Mt. Lowe Trail Camp along the way. For those hoping to climb some of the great peaks of the San Gabriels, this route passes quite close to Mt. Disappointment, San Gabriel Peak, Mt. Markham, and Mt. Lowe. There is a significant amount of exposure, and hikers and trail runners will need to make sure that they are properly equipped for the adventure. One can strategize the best starting place and direction depending on the time of year. For example, the section of this route along San Gabriel Peak Trail, Mt. Lowe Road, and El Prieto Canyon is notably exposed, and it might be smart to start early in the morning with this section during hot summer months. During the winter and spring, significant, sometimes hazardous, water crossings are often necessary along the Gabrielino Trail, whereas during the dry summer months, seasonal streams may run dry. Poison oak is also a less-enjoyable hazard throughout the route, and can be an issue primarily between Paul Little Picnic Area and the turn-off for Switzer Falls on the Gabrielino Trail. Adventure Passes are required to park at Switzer Falls, Red Box Picnic Area, and Millard Falls.