A California man was lost on American Creek in Katmai National Park when his raft flipped/NPS

A California man was missing after a raft flipped while running American Creek in Katmai National Park and Preserve in Alaska. While the 72-year-old had extensive experience rafting in Alaska, he was not wearing a personal flotation device at the time, according to a park release.

The Sacramento man, whose name was being withheld pending notification of next of kin, was last spotted floating down the creek on Tuesday. Three people were in the raft when it flipped. Two of them made it to opposite shores and were able to hike, on their respective sides of the creek, downstream to camp. The people at the camp used a satellite telephone to contact a nearby lodge and report the incident.

An extensive search of the area was performed by a rafting crew, helicopters, and fixed wing aircraft. NPS rangers received assistance from Rainbow River Lodge, the U.S. Coast Guard, and the Alaska State Troopers.

As of Thursday night, no signs of the missing man had been found. While formal search efforts were suspended, bush pilots that operate in the area were planning to continue searching.

American Creek is a remote, 40-mile-long river, renowned for its fishing, according to park information. No roads access the river, so most visitors arrive via float plane. Float trips usually run 7-10 days.

"The river changes significantly from beginning to end, providing a wonderful variety of water," the park's website says. "Like many rivers, the technical difficulty of the trip is dependent on water levels. Higher water levels or a flooded river can create a more challenging trip. Some sections of American Creek are technical regardless of water conditions."