F10-19: Tewson edges Muhlner in a 20-second thriller at the top of Tahoe

• Tamsin Tewson wins in 2:15:13, closing with the 9th-fastest women's split on the Siberia→Finish leg to seal it.
• Zoe Muhlner finishes 2nd in 2:15:33 — just 20 seconds back — after posting the 20th-fastest women's split on KT 22→Siberia.
• Jillian Chalstrom, 17, rounds out the F10-19 field in 2:46:19, finishing with the 66th-fastest women's split on Siberia→Finish.

Three finishers, 16.8K of sky-high trail between 6,200 and 8,000 feet, and a 20-second verdict — the F10-19 race at Broken Arrow 2025 was as tight at the top as the thin Tahoe air would allow.

Tamsin Tewson of San Francisco came in as the winner, but the race unfolded as a genuine chase. Muhlner, running out of Washington, DC, held the stronger position through the middle of the course — her 20th-fastest women's split on the KT 22→Siberia segment showed she was moving well through the technical heart of the race, and at that checkpoint she sat 23rd among women, matching Tewson's position heading into the final stretch. The gap between them was razor-thin, and the race was very much alive.

Then came the Siberia→Finish leg, and that's where Tewson made her decisive move. Her 9th-fastest women's split on that closing segment was a genuinely elite effort — one of the sharpest finishes in the entire women's field — and it was enough to put 20 seconds of clear air between her and Muhlner at the line. Tewson crossed in 2:15:13 at a 12:05/mile average; Muhlner answered in 2:15:33 at 12:07/mile. The finish times were close — the closing efforts were not. Tewson ran Muhlner down, or more precisely, ran away from her, surging from 35th to 23rd among women on that final leg while Muhlner slipped from 23rd to 25th.

Jillian Chalstrom, just 17 years old and racing on home terrain out of Truckee, finished 3rd in 2:46:19 — a 14:52/mile effort across a course that punishes anyone who underestimates the altitude. She closed with the 66th-fastest women's split on Siberia→Finish, moving from 90th to 81st among women in the final leg and showing she had something left when it mattered.