The body of Chenoa Nickerson, 33, was discovered by a commercial river trip on the Colorado River about 30km downstream of where she went missing on Thursday, the US National Park Service said in a statement.

Nickerson, from the Phoenix suburb of Gilbert, was swept into Havasu Creek without a life jacket, the park service said.

Havasu Creek is a tributary of the Colorado River that joins the larger waterway just before it enters Arizona’s Grand Canyon National Park.

The aerial, ground, and rescue vehicle search was concentrated on the confluence of Havasu Creek and the Colorado River, the park service said.

The creek also runs through Havasupai tribal lands, where tribal leaders asked Arizona governor Katie Hobbs for flood assistance, the governor’s office said in a statement.

The state provided assets including a UH-60 Blackhawk helicopter for evacuation assistance and a National Guard deployment, the statement said.

The Arizona National Guard said on Saturday the Blackhawk helped evacuate 104 tourists and tribal members out of a canyon.

The Havasupai Tribal Council on Saturday announced it had closed its lands to tourists until further notice due to extensive flooding.