Search crews used sirens and flashing lights through the night, then set out again at dawn Wednesday, hoping to find a cross-country skier missing in the forests of western Colorado.

Dan Walker, 54, left his wife and daughter Sunday night after the three got lost during a ski outing, hoping to find help. They were rescued, but he hasn't been seen since. After using lights and sirens to try to attract his attention, a full-scale search resumed, said Susan McBurney, the Mesa County Sheriff's Office spokeswoman.

Walker told his family he had seen some car lights and was going to get help, McBurney said. "He did leave a lot of gear with the two women," she said. "We don't know how much more gear he had for himself."

Rescuers used snowmobiles and snowshoes Tuesday to search for Walker through 8-foot-deep snow and asked residents near the search area to check any remote buildings on their property. Rescuers were in a race with time to find him before a cold front arrived in Colorado with subzero temperatures.

"This individual has been out in the conditions for the past two nights," McBurney said. "The longer he's out there, the more at risk he is."

Rescue crews found Debra Walker, the couple's 18-year-old daughter, Camille, and their dog shortly after 8 a.m. Tuesday. The women were picked up in an area about 3 ½ miles from the Mesa Lakes Lodge (search) at about 9,800 feet.

Both women and their dog had huddled together for warmth underneath a tree, McBurney said. Camille was treated and released; Debra Walker was listed in fair condition.