In 1996, a couple college students went on a beer-fueled mission to check out girls and ended up stumbling on what would be one of the most historic, and controversial, archaeological discoveries in US history.

The US Army Corps of Engineers has ruled that the 9,000-year-old skeletal remains (the oldest in North America) of the Kennewick Man belong to a Native American tribe — ending a long and tedious legal battle that began when the two 21-year-olds pulled the human skull out of the Columbia River in Kennewick, Washington.

For 20 years, the Kennewick Man (known to Native Americans as the Ancient One) was locked away while scientists fought against a coalition of five Native American tribes for the right to study the remains. The Native Americans had claimed ownership under the Native American Graves Protection and Repatriation Act of 1990.

The Umatilla tribe wanted to perform a customary burial, the denial of which was “sacrilegious and inhuman,” an Umatilla leader told the Philadelphia Inquirer in 1998.

But scientists weren’t convinced of the skeleton’s ancestry, hoping the remains would reveal a previously unknown group of humans. A paleontologist told the Denver Post in 1997 that burying the Kennewick Man “would be like burning the great library of Alexandria.” Eight scientists filed a lawsuit stating that Kennewick’s unfamiliar characteristics suggested a different origin, making it exempt from federal repatriation laws.

But in June 2015, Nature published a report of DNA results confirming that the skeleton is, in fact, related to modern Native Americans. That report led to the Corps of Engineers’ final decision.

“After 20 years, it acknowledges what we already knew and have been saying since the beginning,” a representative of the Confederated Tribes of the Umatilla Indian Reservation told the Associated Press.

The Kennewick Man will remain in a Seattle museum until the Corps of Engineers determines which of the five tribes — the Nez Perce, Yakama, Wanapum, Colville and the Umatilla — will receive the remains for final burial.

Tribe leaders are expected to cooperate with whoever wins custody, and plan to keep the burial spot secret from the public.