Nearly 50 rescuers searched a rugged hiking area in sometimes knee-deep snow Sunday for a Castle Rock woman who has been missing for four days.

But there were no signs of Carolyn Gjendem, 52, who may have gone hiking in the Pike National Forest at the edge of unincorporated Douglas County, said Douglas County Search and Rescue spokeswoman Debrah Schnackenberg.

Gjendem's daughter reported her missing Thursday morning, and rescuers were notified Saturday night that Gjendem's car had been located. Local residents called about the car after seeing it parked at the Jackson Creek Road winter gate that marks the forest area, Schnackenberg said.

Search crews immediately went into action Saturday and made a "hasty search" of the area from 10 p.m. to about 1:30 a.m.

On Sunday, 47 rescuers from a variety of agencies fanned out over the area all day until around 7 p.m. They were aided by two snowmobiles, four all-terrain vehicles and three search dogs.