The Arizona Geology Summer 2022 issue is now available online.
The feature article, “Get to the Boats! Fatal Debris Flow at Grand Canyon’s Tatahatso Beach, 14 July 2021,” describes a singular debris flood/flow event that sent 32 whitewater rafters scrambling for their lives. This occurred at Colorado River mile 37.9, just downstream from Tatahatso Wash in Grand Canyon National Park. The debris flood was fueled by a torrential monsoon storm which dumped ~ 1.25 to 1.75 inches of rain between 5:00 and 5:40 p.m. Rafters setting up camp on Tatahatso Beach were overwhelmed by a debris flood that fell ~400 feet from the overhanging Redwall Limestone.