Authorities in the US have finally discovered the identity of remains found near the Hoover Dam 15 years ago using DNA technology.

Roadside workers stumbled across human bones near the hydroelectric power plant on the border between Nevada and Arizona back in November 2009, the Mohave County Sheriff’s Office (MCSO) said.

One of the two workers, who was taking a break from pouring cement along the Highway 93 widening project at the time of the discovery, saw what appeared to be a human bone sticking out on the side of the road. According to reports, they then found more after taking a closer look.

A search revealed “a sun-bleached pair of blue jeans, a damaged white towel, a sun-bleached red t-shirt, a black athletic shoe and a green sleeping bag” along with the remains, but the identity of the deceased would remain unsolved for years.

But after years of investigations and testing, authorities have finally identified the body as that of William Herman Hietamaki, a Michigan man last seen by his family in 1995.

However, the identification has taken many years, with various setbacks along the way.

Two years ago, the sheriff’s office submitted samples in the hopes of identifying what was then classed as a John Doe, a placeholder name given to bodies that can’t be IDed.

The Independent reports that one was sent to the Arizona Department of Public Safety lab to obtain a DNA profile that could be submitted to the Combined DNA Index System (CODIS), while another was sent to the University of North Texas.

Unfortunately, these efforts to identify the body didn’t prove successful. However, this April, a genetic testing lab in Texas, Othram, announced that a genealogy grant had been obtained for further testing, which proved to be a turning point in the cold case.

A DNA profile was created using a sample, and after it was added to a genealogy database, investigators determined that the unidentified man “was a descendant of ancestors born in the mid-1800s and residing in Michigan.”

They then used the information to interview possible relatives, including his siblings and became aware of Hietamaki, known for his “nomadic lifestyle” and penchant for hitchhiking, the Sheriff’s Office.

Born in April 1950, Hietamaki, who went by his middle name Herman, attended high school in Trout Creek, Michigan, and mechanics school before setting off to travel around the country. Records show he spent some time living in Las Vegas, Nevada.

But he disappeared and was last seen by his family in 1995 when he visited his sister in New Mexico.

Through further testing, authorities were able to confirm that the remains were those of Hietamaki.

Because of the state of his remains, investigators weren’t able to determine an exact cause and date of death, but he is estimated to have died between 2006 and 2008, at which point he would have been 56 to 58 years old.

However, Hietamaki was known to suffer from epileptic seizures, which may have played a role in his death.

The MCSO said: “The Mohave County Sheriff’s would like to thank Othram Inc. for their work in this case and for obtaining grant funding to enable the forensic genetic genealogy investigation to be completed.

“Hietamaki’s family now has closure due to their dedication in identifying John and Jane Does,” the force added.