A 67-year-old man has died after a motorboat overturned during a Colorado River trip inside the Grand Canyon National Park, officials said.

Park officials said the boat flipped just after 2pm on Saturday at Bedrock Rapid, which rafting experts say is a large rocky island which divides the river into left and right channels.

Emergency medical personnel treated four people and took them to the South Rim, officials said.

Authorities say their injuries are not critical.

Park officials identified the victim as Ronald Vanderlugt but did not immediately say where he was from.

Mr Vanderlugt was on the fifth day of his trip, they said.

Members of the river trip group pulled him out of the water, saw he was unresponsive and began CPR, park officials said.

They said park rangers were flown in by helicopter but Mr Vanderlugt could not be resuscitated.

The boat overturned in the rapid when it came up against a rock, said John Dillon, executive director of the Grand Canyon River Outfitters Association, which represents outfitters permitted in the canyon.

Mr Dillon said some of the passengers decided against continuing the trip, operated by Western River Expeditions.

An investigation will be conducted by the National Park Service and the Coconino County Medical Examiner.