As Sue Clark watched the snow drifts deepen around her Blue Ridge mountaintop home, the flu she'd been fighting off grew worse. By Tuesday afternoon, the 77-year-old woman was becoming weaker and appeared to be getting dehydrated. Her son-in-law called 911 in the western Loudoun County town of Round Hill.

Then they waited.

Help would come eventually, but the effort would stretch over two days as rescue workers inched up five miles of slick mountain roads, enlisted heavy earth-moving equipment from state road workers and, finally, slogged their way in on foot to reach Clark yesterday morning. She was taken to Loudoun Hospital Center, where she was in stable condition last night with what her son-in-law, John J. Denale, described as pneumonia.

The first six hours of the rescue effort were the most harrowing, said paramedic Peggy Childs, one of those who responded to the 911 call. "The wind was horrible," said Childs, recounting her trip up Mount Weather with three other paramedics Tuesday afternoon and evening. "The visibility was zero. . . . [But] we had to get to her."

Wearing canvas coveralls over cotton sweat shirts and thermal underwear, Childs and the others soon found that the usually scenic mountain roads had turned treacherous in the wind-sculpted landscape. Snowdrifts blocked the first route they tried. A neighbor with a backhoe tried to clear a path, but couldn't.

The crew then called the Virginia Department of Transportation, which sent a pickup equipped with a plow. It, too, got stuck.

The paramedics next tried a different route, only to meet up with a 20-foot drift. As the sky darkened and the temperature plummeted, a VDOT dispatcher located a highway grader and sent it to help. But even the grader bogged down in the heavy snow.

Denale, a Fairfax veterinarian, called Round Hill again, proposing to hike halfway down the mountain if one of the paramedics would hike halfway up with intravenous fluids to see his mother-in-law through the night.

Childs, 41, immediately volunteered. The mother of six zippered her coveralls up to her chin and braced for the 300-yard dash to the grader, which would take her as far as the unpassable stretch of road. "My eyes were watering, and the snow felt like sharp pins hitting my face," she recalled yesterday, relating how she made it up the mountain and handed over the IV fluids, then hiked back down again.

Early yesterday, a crew from Round Hill was out again, determined to reach Clark. VDOT's David Piper arrived with a much larger vehicle equipped with a special plow for big drifts and was able to churn all the way up to Clark's road. The paramedics followed in their ambulance, walking the last quarter-mile.

A half-hour later, when the grader finally got to Clark's driveway, the ambulance pulled up alongside.

"I'd do it again because that's what I'm trained to do," Childs said of the memorable rescue. "It was definitely an experience I'll never forget."

Denale praised the paramedics and VDOT workers. "They made quite an effort to get here," he said, noting that conditions were so bad Tuesday that he had decided it would have been more dangerous for Clark to have tried to take her out of the house.

"She's resting comfortably," he said yesterday. "She's doing fine. It's just bad luck that it happened on the worst day of the year."