Grim discoveries emerge as Lake Mead's water levels drop

The remains — a jawbone with teeth and dental fillings, and some rib bones — were found by a woman and a man and his daughter Aug. 16 at Boulder Beach on the Nevada side of the Lake Mead National Recreation Area.

National Park rangers and Las Vegas police recovered the remains. The victim’s identity and cause of death were not known.

"A non-criminal, dead body report was taken for the remains," the Las Vegas Metropolitan Police Department told USA TODAY in a statement.

The Guardian reported some experts believe more remains will be found because Lake Mead is 20 miles from Las Vegas, a historic center of organized crime.

Lake Mead is an artificial reservoir upstream of the Hoover Dam on the Colorado River. It straddles Clark County, Nevada, and Mohave County, Arizona. Much of the Clark County region reported moderate drought as of Aug. 18, according to the U.S. Drought Monitor.

The reservoir’s water level has dropped more than 175 feet since 2000, according to Bureau of Reclamation data. That’s a net water loss of nearly 6 trillion gallons.

Researchers say rising temperatures driven by climate change are intensifying drought and reducing runoff across the Colorado River Basin. The Lake Mead surface is now close to the same level as it was in March 1937, as the lake was filling up behind the newly finished Hoover Dam.

Because of that water loss and the grisly discoveries on the drying lake bed, Lake Mead now offers a look at what's ahead from climate change and a glimpse of American West history.

What's been discovered and where

May 1, 2022: Body in a metal barrel

A body stuffed inside a rusting metal barrel was found by boaters near Hemenway Harbor boat launch of the Lake Mead National Recreation Area, close to Las Vegas, on May 1.

Police say the barrel was in an area that would have been 100 feet underwater and several hundred feet from shore in the 1980s. It's the only one of the five bodies found that's being treated as a homicide.

Based on clothing and shoes, it's believed to be a man who died by a gunshot in the mid-1970s or early 1980s, according to Las Vegas police. The identity has not been established.

May 7, 2022: Skeletal remains at Callville Bay

Paddleboarders found human remains in the Callville Bay area. They were identified as those of Thomas Erndt, 42, of Las Vegas, discovered at the bay May 7 in the Lake Mead National Recreation Area.

Erndt jumped off a boat on Aug. 2, 2002, according to news reports at the time. He was reported missing and presumed to have drowned, but an official cause of death has not been determined.

The Clark County coroner's office used forensic analysis, including DNA samples and X-rays, to identify the remains.

July 25, 2022: Partial remains found at Swim Beach

Partial human remains were found at Swim Beach near Boulder Beach at the Lake Mead National Recreation Area. Additional fragments found Aug. 6 and Aug. 16 were determined to have belonged to the same person, Claude Russell Pensinger, who disappeared in 1998.

Aug. 6, 2022: More remains found at Swim Beach

Additional skeletal remains were discovered at Swim Beach on Aug. 6, according to the National Park Service. The remains were recovered by park rangers and the Las Vegas Metropolitan Police dive team and were later linked to the July 25 and Aug. 16 discoveries and identified as Pensinger.

Aug. 15, 2022: Third set of remains at Swim Beach

A third set of skeletal remains was discovered at Swim Beach on Aug. 15, according to the park service. The remains were later identified as those of Pensinger.

World War II landing craft uncovered

A World War II-era Higgins landing craft used to survey the Colorado River has reemerged from the lake. The craft is less than a mile from Lake Mead Marina and Hemenway Harbor.

The plywood boat, still wrapped in armor plating, had its engine removed and was modified for lake service. The National Park Service told CNN it's unclear if the boat was sunk by accident or on purpose.

Higgins boats were used to land troops and equipment on invasion beachheads. They were used in the D-Day invasion of Normandy in 1944. More than 20,000 Higgins boats of different configurations were built.

National park staff members began conducting scuba dives on the Lake Mead boat in 2006.

Ghost town rises from lake once again

Hundreds of residents of St. Thomas, Nevada, began leaving the town in 1935 after Hoover Dam was finished and Lake Mead started filling in. The town itself began to submerge in 1938.

Founded in 1865, the town is in the northern part of the park near the Overton Arm along the Muddy River. Water levels fluctuated over the decades, and former residents and family members held reunions in 1945, 1963 and 2012.

At Lake Mead's highest level in 1983, the town was 60 feet underwater, though much of St. Thomas has been above water since 2004. Visitors can now walk through what's left of the town.

Lake level is still falling

Lake Mead has the largest storage capacity of any reservoir in the United States. But decades of increasing water demand and drought in the West have caused a continual decline in water levels. This time series shows the gradual shrinkage of Lake Mead’s shorelines, which now sit lower than any time since the 1930s, according to NASA.

About 10% of Lake Mead's water comes directly from precipitation, according to the National Oceanic and Atmospheric Administration. Most of the lake's water comes from melting snow on the western part of the Rocky Mountains.