What happened: Sam Smart, 21, a Mill Valley native entering her senior year at Princeton, spent the past several days running the Dipsea Trail sixteen times between the Depot and Stinson Beach, covering 118 miles in 61 hours and 32,000 feet in measured elevation gain (although she says it was more like 38,000). She finished Monday.
The run raised money for the American Foundation for Suicide Prevention and, by her account, made her the first woman to attempt and complete the "Quad Quad" distance, roughly four times the length of the Quad Dipsea race, and sixteen times the historic Dipsea.
Sam Smart on Monday, August 2, at Depot Plaza after completing 118 miles on the Dipsea route, running sixteen times from the Depot to Stinson and back. (Courtesy of Sam Smart)
The background: Smart, a Tam High graduate, grew up hiking the Dipsea with her family and discovered ultrarunning at 16, during a pandemic-era PE assignment that sent her down a YouTube rabbit hole on ultrarunner Courtney Dauwalter. She said she was going through a difficult period in her personal life at the time and that the sport, and the trail specifically, carried her through it. "I would not be here without ultrarunning," she told the Briefing.
She ran the standard Dipsea and the Quad Dipsea that same year, then a 50-mile version of the trail at 17. By 18, she had run the Golden Gate Trail Classic 100K and then became the youngest person to run the foot race over Mount Tam, a course from San Francisco to the summit, on to Fairfax, and back to San Francisco. She rows for Princeton, where the past three years brought an experimental rib surgery, a torn lat, herniated discs and a failed epidural that punctured her dura, causing a spinal fluid leak.
Smart said the physical setbacks put her back in a difficult place this year that felt similar to what she experienced at 16, and that returning to the Dipsea was part of what pulled her through it again. “I was just thinking about the Dipsea. That’s really where that 16-year-old girl found herself again,” Smart said. "I could cry right now, just talking about trail running," she said, her voice trailing off.
Smart on the Dipsea trail, running through the second night. (Courtesy of Sam Smart)
The breaking point: Smart had aimed to finish in under 40 hours. Hip and knee pain nearly ended the attempt around mile 80, when she sat on the trail crying to her mother, convinced she would not finish. Sitting there pain free, she said she came up with a new rule: if she could sit without pain, she could keep going. That became her mindset for the last 40 miles, taken one step at a time.
For the final stretch, she descended stairs backward, leaning on trekking poles, because going down forward had become too painful to manage. San Francisco Running Company and the Depot Cafe and Bookstore sponsored an aid station, and volunteer ultrarunners paced her through the back half alongside her mother.
The community had heard of Smart’s attempt, and more and more people started making the trek to the Depot to cheer her on, including Brian Muir, who brought his bagpipe and played ‘When The Battle Is Over’ as she took her last Dipsea steps.
The tribute: Smart ran with a pin on her vest reading "KG," for Kerry Grundlingh, a Princeton rowing teammate who died in July 2025 after being struck by a car while cycling in her hometown of Johannesburg, South Africa, according to Princeton Athletics. Grundlingh was a two-time Ivy League Championships medalist who rowed in the varsity eight that won gold at Ivies in her final season.
She died the day before Smart went into surgery. Smart said Grundlingh was a big motivator for her during the run.
What's next: Smart said she plans to write her senior thesis on women in ultrarunning, a sport she said becomes more evenly matched between men and women at extreme distances. She has not ruled out attempting another long ultra.
📨 Know anyone who has hiked or run the Dipsea before? Forward this newsletter to them.
New details emerge on what drove Mill Valley's power shutoff
The background: July 15's shutoff cut power to about 2,017 Marin customers, almost all in Mill Valley, from around 6pm until mid-morning Thursday. PG&E cited high winds, low humidity, and dry fuel conditions in its July 14 news release.
The Briefing's own review of PG&E's weather stations found a mixed picture, milder readings near the outage area and stronger wind and dryness higher on Mount Tam. At that time, PG&E had not responded to the Briefing's questions about which conditions drove the call. Since then, two new pieces of information have arrived.
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