The incident occurred in an area of the river called Bedrock Rapid in Grand Canyon National Park, NPS said in a tweet Saturday.
“Today at 2:12 p.m., we received a report of a flipped motorboat on the Colorado River at Bedrock Rapid. One fatality has been confirmed; SAR [search and rescue] is underway to treat and transport injured patients. Incident is ongoing; no further information is available,” Grand Canyon National Park Service said.
A spokesperson later told CNN in an email that four people had been injured in addition to the fatality.
On its website, rafting company Western River Expeditions says a large rock splits the Colorado River’s current at Bedrock Rapid.
“The best run is on the right side, which requires adept and precise handling to bring a craft around the rock and into calm water. The left side is an unforgiving place, as the river pinballs through a narrow rock studded channel,” it says.