LAS VEGAS (KLAS) — Boaters and swimmers have discovered the remains of four people at Lake Mead since May, but not all of their deaths are considered suspicious.

The ongoing severe drought is leading to the discovery of more and more human remains at the lake. What were areas far out in the water — are now new shoreline.

May 1: Body found in barrel

Boaters discovered a body in a barrel on May 1. The 8 News Now I-Team first reported the discovery that day. Police said the person, believed to be a man, was shot. Police believe the barrel was fully intact when it was dropped into the lake.

The person is suspected to have been murdered in the late-1970s or 1980s, investigators said in May. The victim’s clothing and shoes were sold at Kmart in the mid-to-late 1970s.

Boaters discovered a body in a barrel on May 1. (Shawna Hollister/KLAS)

Homicide detectives have requested DNA from multiple families to help solve the case, Metro police said. The families were chosen from several unsolved missing person cases from that time.

The FBI is assisting with the investigation. Lake Mead and its surrounding washes were popular dumping grounds for criminals.

May 7: Callville Bay remains

Skeletal remains discovered at Lake Mead on May 7 are believed to be from a person who was in their 20s or 30s when he or she died, a spokesperson for the Clark County coroner told 8 News Now last week.

Police and park officials have determined the death was not suspicious.

The skeletal remains discovered at Lake Mead in May 2022. (Lindsey Melvin/KLAS)

A Las Vegas native told 8 News Now in June that he believes the remains could be his father who drowned in the area in the 1950s.

Daniel Kolod was 22 when he drowned in Callville Bay in 1958. His body was never recovered. (KLAS)

Daniel Kolod was 22 when he drowned in Callville Bay in 1958. His body was never recovered.

The Kolods have asked the Clark County coroner’s office to submit their DNA for testing.

July 25: Swim Beach

The third set of remains was found floating near Swim Beach in late July. The partial torso was floating without its limbs.

Partial human remains discovered at Lake Mead on July 25, 2022. (Jesus Catalan/KLAS)

Las Vegas Metro police are not involved in the investigation, indicating the death is not considered suspicious.

The coroner’s office has not officially indicated how the person died.

August 6: Swim Beach

Another set of skeletal remains was discovered at Lake Mead last Saturday morning near where the third remains were found.

Rangers responded to an emergency call and set a perimeter to recover the remains with support from a dive team from Metro police.

A formerly sunken boat sits upright into the air with its stern stuck in the mud along the shoreline of Lake Mead at the Lake Mead National Recreation Area, Friday, June 10, 2022, near Boulder City, Nev. Lake Mead water has dropped to levels it hasn’t been since the lake initially filled over 80 years ago. (AP Photo/John Locher)

The identification of all the remains could take months, if not years. Widespread DNA sampling is a recent phenomenon.

Getting a sample from the remains and matching it with a living family member is the only way to potentially solve these mysteries.

Since Lake Mead’s filling in the 1930s, 300 people have drowned in its waters, park service officials previously told the 8 News Now I-Team. The decade with the most drownings is the 1990s, records showed.

Tips can be submitted anonymously through Crime Stoppers by calling 702-385-5555 or at Information can also be sent via text by sending “CRIMENV” and then your message to “CRIMES” (274637). Crime Stoppers offers a reward for information that leads to an arrest.