Authorities have been searching since Friday for an Arizona woman reported missing after being swept away by flash floodwaters hit an area of Utah’s Zion National Park as monsoon rain storms hit the Southwest.

National Park Service officials reported that more than 20 rangers and members of the Zion Search and Rescue Team were in the Virgin River area Sunday looking for Jetal Agnihotri, 29, of Tucson.

Agnihotri was one of several hikers who were swept off their feet Friday afternoon by the sudden rushing water in southern Utah near the Arizona border. The area called the Narrows in the park, is known for its remarkable red-rock cliffs and narrow canyons.

Authorities were able to find all but one of the hikers on high ground that were stranded until water levels receded. One person was hospitalized.

Heavy rain in the area can turn hiking in the park dangerous as the moisture runs off the desert land and quickly fills canyons with water, rocks and heavy debris. During the summer when seasonal afternoon thunderstorms develop, the weather conditions can lead to flooding in the usually dry washes.

Authorities have closed down the Narrows and Riverside Walk of the National Park until further notice to carry out search and rescue operations for the missing hiker.