Medical examiners with the Los Angeles County Coroner’s Office identified Benjamin Marquez IV, 31, of Castaic, as the man killed in a solo-vehicle crash that left one dead and sent another to the hospital Saturday.

California Highway Patrol officers received reports of an off-road crash shortly after 1 p.m. Saturday after a passerby had located an overturned vehicle in the hills approximately 1 mile west of The Old Road on Oak Valley Road, according to a CHP news release.

Due to its remote location on a dirt road, the crash site had gone unnoticed for some time, with initial interviews from the passenger stating they were out there since Thursday, according to Officer Josh Greengard, spokesman for the Newhall-area CHP Office.

“CHP Newhall units responded along with (L.A. County Fire Department) and located an overturned pickup truck” with rollover damage, the release stated.

“One (person) was (dead on arrival) and another patient was transported,” said a spokesman for the Los Angeles County Fire Department.

The unidentified passenger, a Castaic man in his 30s, was said to have suffered major injuries, including two broken legs and suspected head trauma, and was airlifted to Henry Mayo Newhall Hospital by L.A. County Fire Copter 22, per CHP reports.

“A lot of investigation will have to take place before we know more,” Greengard said Saturday.

Further details about the cause and/or circumstances surrounding the crash are under investigation and currently unknown as of Monday, according to CHP officials.

Signal Staff Writer Caleb Lunetta contributed to this report.