The skeleton of a Long Island man who disappeared after venturing onto a Native American reservation earlier this year was found Thursday scattered along a highway — suffering from what a family friend described as “horrific violence.”

Isaiah Henriquez, 20, was identified Saturday as the human remains found by a driver who had pulled onto a wooded area of exit 40 on the Southern State Parkway in Islip, state police announced.

Family members were told authorities were treating the case as a homicide because of the “horrific violence” found alongside the shoulder, according to a friend.

“There was blood in the area and there was a body, other material that just indicated that there was a violent scene,” Henriquez’s former classmate Nicholas, who opted not to disclose his last name, told The Post.

State police said it is too early to determine a cause of death.

Suffolk County police have been searching for Henriquez since he vanished on the Poospatuck Reservation in Mastic on April 8.

The young man had been dropped off at the Suffolk County reservation at 7:30 p.m. after spending time at a party in Brentwood, a town more than 20 miles away from Poospatuck, his mother told The Post in May.

Friends said Henriquez was last seen at the Poospatuck Reservation in Mastic.

Friends said he had visited the Unkechaugi people’s reservation before to buy weed, and told partygoers he would be back “quick” the night be disappeared.

“It’s kind of crazy and no one knows why, but he got into a Lyft and took him out of the Indian Reservation out east on Long Island,” said Nicholas, who has been in communication with Henriquez’s best friend and cousin.

“The reservation or the police really don’t have any reasoning as to why he went out there or if he went out there willingly. The only thing that they know at this point is someone reported skeletal remains on the Southern State, which is back where we live, where the party was.”

Police at the scene.
A driver noticed skeletal remains in a wooded area along the highway near the town of Islip.
NBC New York

Police at the scene.
Investigators told family they were treating the death as a homicide, insiders said.
NBC New York

Police at the scene.
According to friends and family, blood was found at the scene.
NBC New York

Henriquez’s phone went dark after several hours, which was out of character for the communicative Long Islander, his mother Diana said at the time.

Another man disappeared on the same reservation just two days after Henriquez, sparking concerns that nefarious gang-related activities might be at play, though the 27-year-old man was found unharmed in the area a few weeks later.

Henriquez had left a party in Brentwood and told friends he would be back “quick” the night be disappeared.

Nicholas said Henriquez had been living a normal and healthy life at the time of his disappearance

Requests for comment made to the Unkechaug Indian Nation Chief and the federal Tribal Law Enforcement Authority were not immediately returned.