The Nevada Highway Patrol said the crash occurred at about 3 a.m. on Interstate 15 near Mesquite on the Arizona border, KLAS-TV, Las Vegas, reported.
Troopers said the driver of the SUV, a Dodge Durango, may have been drunk when the vehicle struck a Chevy Astrovan from the rear.
Five of the seven people in the Astrovan died in the crash. The other two, and two in the Durango suffered critical injuries.
Notable deaths of 2014 [PHOTOS]