Flash flooding is common enough around the crescent-shaped region from Dallas through the Hill Country, the area earned the nickname "Flash Flood Alley."

One of Texas' most popular rivers flooded over the weekend and contributed to Texas' catastrophic flooding that claimed over 80 lives, including two dozen children at Camp Mystic. Here's what to know about the layout of the river and the role it played in one of the state's deadliest flash floods in modern history.

More than 100 people have been confirmed dead in severe flooding in Central Texas as emergency workers continued to look for dozens who remained missing.