Amanda Eller, 35, went hiking in Maui's Makawao Forest Reserve on May 8 but became lost when she walked deeper in the reserve, which covers more than 2,000 acres, instead of heading back to her car as she believed.
Rescuers in a helicopter hired by her family spotted Eller on Friday afternoon in a ravine by a waterfall, miles from her vehicle.
"Sure enough, God willing, she was right there," Javier Canetellops, a search coordinator who was in the helicopter, told reporters. "Unbelievable."
Eller, who also works as a physical therapist, was malnourished, shoe-less, and had a broken leg and torn meniscus in her knee, as well as sunburn and scrapes. She was airlifted to a hospital and expected to make a full recovery.
Friends had launched a "Find Amanda" campaign on Facebook, and just an hour before she was rescued they offered a $50,000 reward for information. Volunteers spent days scouring the thick forest around the trailhead where she parked.
"Elated. Excited. Ecstatic," Eller's mother, Julia, told NBC News affiliate KHNL in Honolulu. "I can't even put it into words I'm so incredibly grateful."