The crash happened at 11:41 a.m. near Rich Road in Dalton Township.
The Muskegon County Sheriff's Office said all three victims were in the SUV and are believed to be from the Muskegon area. Their names were not immediately released.
The preliminary findings by police investigators indicate the Chevy Tahoe was southbound on Holton Road when it crossed the centerline, striking the northbound box truck.
Two occupants of the Tahoe were ejected from the vehicle and pronounced dead at the scene. Another passenger in the Tahoe was transported to Hackley Hospital in Muskegon in critical condition.
The driver of the box truck declined medical attention and is cooperating with investigators.