Second-place finisher Amanda Stevens led Jackson by almost eight minutes getting out of the water, but the 31-year-old Bend, Ore. resident and former Ivy League hockey player used her cycling background to make up the time and had the fastest run to complete the come-from-behind victory.
"To get my first full win here felt incredible," Jackson said. "It felt like a home race."
Stevens crossed the clock with a time of 9:40:16, almost 17 minutes behind Jackson.
Kim Schwabenbauer came in third, 10:03 behind Stevens. Amber Ferreira and Kary Blakemore finished with times under 10 hours to place fourth and fifth, respectively.
Tamara Kozulina (Ukraine) was the top international finisher with a time of 10:09:29 to earn the seventh spot. Anne Basso (France) finished tenth with a time of 10:21:24.