LAS VEGAS (KLAS) — As Lake Mead’s water levels receded and human remains nearly 50 years gone surfaced, a half-century-old investigation is returned to the spotlight.

Larry Millwood is the proprietor of “3rd Reef Divers” based in Henderson, which offers diving training. He believes there may be additional human remains yet to be unearthed beneath the depths of Lake Mead. Although Millwood insists that he is not actively seeking out such findings, he and his crew are equipped to handle the situation should it arise.

“If we do happen to come across something,” said Millwood. “We’ll mark it and then let the authorities know.”

Larry Millwood is ready should he or his team make a grisly discovery under the surface of Lake Mead. | Photo: KLAS

Millwood and fellow diver Mitchell Claffey say they haven’t personally found remains. However, they have made some discoveries, including weapons. When Donald Smith, 39, from North Las Vegas, vanished during a boat ride at Lake Mead near Calville Bay in April 1974, several weapons became a part of the investigation.

Documents obtained by the 8newsnow.com Investigators indicate that Smith had left his home at approximately 1:00 p.m. on the day of his disappearance. His wife said Smith had been drinking, but that he wasn’t drunk. She said he had taken his handgun with him and had loaded a shotgun into the cabin of his boat.

Documents obtained by the 8 News Now Investigators surface a centuries-old case. | Photo: KLAS

Approximately two hours later, two of Smith’s longtime friends, floating 150 feet away from his boat, said they saw him fall back into the lake with his hands thrown up. About one minute later, they said they arrived at where Smith had dropped into the water and found one deck shoe floating on the surface. After diving in to search for him, they said Smith was nowhere to be found.

National Park Service investigators arrived and were unable to locate Smith. Neither, documents say, were they able to find Smith’s weapons on the boat or in his vehicle. Investigators questioned Smith’s friends, the first people on the scene after he fell into the water. Smith’s friends said they were willing to undergo a lie detector test. The investigators later determined that it was impossible for anyone to conceal the weapons since rangers were present at the location. Instead, investigators said it was likely that the guns were stolen from Smith’s vehicle, which had been left unlocked. That kind of theft was common in the area at that time.

After a search that day, and the next, investigators determined the water was too deep. The Park Service didn’t have enough resources and precise information on where Smith drowned was unavailable. They concluded that Smith either slipped or was knocked off balance by a wave. The coldness of the water and Smith’s breath being knocked out of him caused his quick disappearance underwater without a trace, investigators determined.

The team at “3rd Reef Divers” believe there may be more to discover beneath the waters of Lake Mead | Photo: KLAS

Nearly 50 years later, a diver found a human bone in the mud near the fuel dock at Calville Bay. Over the next few days, National Park Service divers found a pair of jeans, more remains, and a wallet and credit cards belonging to Smith.

The maximum depth of that area when Smith’s remains were found was documented at 47 feet. In 1974, that same area was as deep as 160 feet.