More human remains found in Lake Mead. Amid historic drought, what else has been discovered?

Another set of human remains was discovered Monday in Lake Mead – the third body found in less than three months.

The grim discoveries, one of which appears to be decades old, are being uncovered now only because of a prolonged drought that has dropped water levels in the nation's largest reservoir to their lowest levels since it was first filled 85 years ago.

Context: Water levels in Lake Mead, on the border of Arizona and Nevada, have plummeted to their lowest point since 1937. Human remains, along with decades-old items, have been discovered as levels dropped.

Why this is important: The water supply for 25 million people in the Western U.S. and electricity for 350,000 homes are at risk.

Remains found this week in Lake Mead

The National Park Service said the latest set of human remains were discovered Monday afternoon.

Park rangers arrived and recovered the remains, according to a news release.

Officials did not release any information about an identity or a cause of death, though the Clark County Medical Examiner was investigating.

More on discoveries: Second set of human remains found in Lake Mead amid historic low water levels

'The moment of reckoning is near': Feds warn huge cuts needed to shore up Lake Mead, Colorado River

Two other sets of human remains were discovered in early May. One body was found on May 4 stuffed inside a barrel. Another was discovered on the shoreline by paddleboarders a week later.

Investigators said the person inside the barrel appeared to have been shot, possibly sometime in the mid-1970s to early 1980s, based on clothes and footwear. At that time, Lake Mead was almost completely full, and the water would have been at least 20 to 30 feet deeper.

WWII plane, capsized boats: What else has been found?

Trash, baby strollers and dozens of sunken boats have been found as water levels dropped. A World War II-era B-29 that crashed in 1948 is among the historic finds that are now more assessible to researchers.

Ghost towns and Native American settlements now poke out from the water. Many of the areas were flooded when Lake Mead started filling in the 1930s.

A body in a barrel, ghost towns: What other secrets are buried in Lake Mead?

One is St. Thomas, settled by Mormons, and once an important stopover on the pioneer route from Salt Lake City to Los Angeles. When the lake was full, the surface was 60 feet above the top of the flooded town's tallest buildings, but now the entire settlement has been exposed.

Still hidden beneath the water is the Pueblo Grande de Nevada, also known as the Lost City. There are also caves where Native Americans harvested salt to preserve food.

A drought fueled by climate change

Lake Mead is the nation's largest reservoir. It was created by blocking the Colorado River with the Hoover Dam, and it began filling in 1934. It supplies electricity to about 350,000 homes and water to 25 million across the Southwest.

The lake has been receding for years and is now filled only to 27% of its capacity, according to NASA.

In February, the U.S. Drought Monitor reported 95% of the Western U.S. was experiencing drought, and Lake Mead was noted for its lowest recorded levels. A majority of this “megadrought” can be blamed on human-caused climate change, according to the peer-reviewed British journal Nature Climate Change.

'Megadrought': The intense dry spell in the West is worst 'megadrought' in 1,200 years, new study says

NASA satellite images: Lake Mead water levels plummeting to lowest point since 1937

"The largest reservoir in the United States supplies water to millions of people across seven states, tribal lands, and northern Mexico," NASA Earth Observatory said in a news release. "It now also provides a stark illustration of climate change and a long-term drought that may be the worst in the U.S. West in 12 centuries."

The U.S. Reclamation Commissioner has warned surrounding states that water users would need to make immediate cuts to protect future supplies and power generation.

Contributing: Trevor Hughes

This article originally appeared on USA TODAY: Lake Mead: Third set of human remains discovered amid drought