BOULDER CITY, Nev. – Low water levels at the country’s largest reservoir continue to allow for discoveries of human remains, with the sixth year of the year happening at the Lake Mead National Recreation Area.

The National Park Service said a diver initially found a bone in Callville Bay on October 17, and the next day, a more exhaustive search was conducted, which found more skeletal remains.

The remains have been handed over to the Clark County Coroner’s Office, which will be tasked with determining the deceased’s identity.

The office is investigating at least five other cases of human remains found in or around the lake since May.

So far, only one set of human remains has been positively identified through the use of DNA analysis.

The NPS said bones found on May 7 are believed to belong to Thomas Erndt, a 42-year-old man who reportedly drowned on August 2, 2002.

Rangers said they received a report in 2002 of a man struggling to swim without a life jacket near Callville Bay, and he was never spotted again.

So far, investigators have not linked the cases and caution that they do not know how many people the six sets of remains belong to.

Over the summer, what are believed to be three sets of remains were discovered in an area known as Swim Beach. Authorities have not ruled out the remains belonging to one person but were treating the investigation as three separate cases.

The most recent discovery was found in the same general area as the May 7 human remains, near a marina and camping resort.

By Andrew Wulfeck, FOX Weather