"I would say there is a very good chance as the water level drops that we are going to find additional human remains," Las Vegas police Lt. Ray Spencer told KLAS-TV on Monday.
The lake's level has dropped so much that the uppermost water intake at drought-stricken Lake Mead became visible last week. The reservoir on the Colorado River behind Hoover Dam has become so depleted that Las Vegas is now pumping water from deeper within Lake Mead, which also stretches into Arizona.
Personal items found inside the barrel indicated the person died more than 40 years ago in the 1980s, Spencer said.
He declined to discuss a cause of death and declined to describe the items found, saying the investigation is ongoing.
Police plan to reach out to experts at the University of Nevada, Las Vegas to analyze when the barrel started eroding. The Clark County coroner's office will try to determine the person's identity.
Boaters spotted the barrel Sunday afternoon. National Park Service rangers searched an area near the lake's Hemenway Harbor and found the barrel containing skeletal remains.
Lake Mead and Lake Powell upstream are the largest human-made reservoirs in the U.S., part of a system that provides water to more than 40 million people, tribes, agriculture and industry in Arizona, California, Colorado, Nevada, New Mexico, Utah, Wyoming and across the southern border in Mexico.