Rescuers searched for survivors at Camp Mystic on the bank of the Guadalupe River in Hunt, Texas, after deadly floods swept through the area on July 4.

It took just 90 minutes for the river to rise more than 30 feet. A look at the historic flood levels now etched into Central Texas history.

Follow along for developments on the July Fourth floods along the Guadalupe River in Kerr County and Central Texas.

Flash flood alley is a curved-shaped region about 300 miles long and 50 miles wide in central/south-central Texas, extending from north of Dallas to southwest of San Antonio. Its location, weather patterns, and geology often combine to create devastating floods.

A combination of steep terrain, shallow soil and a moisture-laden weather system that stalled over the Texas Hill Country caused the flash floods that killed at least 79 people Friday. The weather system that caused the flooding was fueled by moist air from the coastal plain that swept up the Hill Country’s steep cliffs,