In what experts call "Flash Flood Alley," the terrain reacts quickly to rainfall steep slopes, rocky ground, and narrow riverbeds leave little time for warning.

The Texas Hill Country has been notorious for flash floods caused by the Guadalupe River. Here's why the area is called "Flash Flood Alley."

The search and rescue efforts are intensifying for more than 160 people who remain missing days after flash floods killed more than 100 people in central Texas. New satellite imagery collected on July 8 shows the aftermath of the devastating flood along the Guadalupe River that swept through the area near Hunt and Kerrville, Texas.

Devyn Smith clung to a tree as muddy, debris-laden water rushed beneath her. She was ripped more than 15 miles from where she and five of her family members had set camp the night before.

The situation evolves daily. Several nonprofit groups that have arrived said they plan to remain on the ground for the next few weeks, providing physical, emotional, and spiritual support.

In Kerr County, Thad Heartfield is leading nearly 100 volunteers searching for flood victims. For him, this mission is personal. His son and three of his son's friends disappeared in the flood.

The flooding brought the Guadalupe to its second-highest point in history, according to the National Weather Service, which urged people in the affected area to move to higher ground.

Lieutenant Governor of Texas Dan Patrick said that least six bodies have been found, including some adults and some children. Some were found in cars, he said