Sherri Papini was still bound with restraints when she managed to flag down a car on Thursday some 140 miles (225km) from where she was last seen.
Police, who say she was released by her captors, are looking for two women in connection with her disappearance.
Ms Papini's husband had reported her missing after she failed to pick up their children from day care.
The motive behind her abduction in Redding, northern California, on 2 November, is still unclear.
County Sheriff Tom Bosenko told reporters Ms Papini was receiving medical attention for non-life threatening injuries at a nearby hospital.
"We are very thankful on this day [Thanksgiving] that she was found safe and reunited with her family.''
A $50,000 (Â£40,200) reward is being offered to find those responsible for Ms Papini's capture.
Investigators had interviewed hundreds of local residents regarding her disappearance and received some 400 tips.
A missing California mother of two has been found three weeks after she was abducted while out jogging.