Morgan Ladlee and her fiancé loaded their backpacks with supplies and began a journey up the mountain that, a week ago, would have taken about five minutes by car.

Now, it felt more like an odyssey. Step by grueling step, they teetered along the edge of a cracked highway, entire stretches of which had fallen into the creek below. They leaped from rock to rock to avoid sinking into thick mud that had fallen from the mountainside. They helped each other up and down ledges and over fallen trees and power lines.

Finally, after climbing 500 feet in elevation, Ms. Ladlee, 22, reunited with her parents and younger brother for the first time since the remnants of Hurricane Helene inundated western North Carolina and killed more than 90 in the state. They embraced tearfully, as if they had been through a battle and survived.

In some ways, they had.

The storm sent torrents of water and mud shooting down from the region’s many mountains and into isolated towns. Places like the tiny town of Bat Cave, N.C., where Ms. Ladlee and her fiancé live, and nearby Gerton, where her parents live, had no way to prepare for the historic deluge, and many are now cut off from the outside world.