The two-car crash happened at around 4 p.m. on Fruitport Road near Walden St. Fruitport Road was closed for about an hour after the crash.
Police said both were "distracted drivers" and the preliminary investigation shows both were at fault.
Ryan Freed, 16, was on his way home from drama practice, his mother said. The Spring Lake Township boy was driving south on Fruitport Road and apparently was reaching for his dropped cellphone when his car crashed into a northbound vehicle.
Mariann Puckett, 65, was driving north and was eating a sandwich, police said. The two cars were either close to or over the roadway's center line when they collided.
Freed was taken to North Ottawa Community Hospital by ambulance and Puckett was transported to Mercy Hospital in Muskegon.
Puckett was still in serious condition Friday morning at Mercy Hospital. Freed was treated and released later Thursday, said officials at North Ottawa Community Hospital.
It took Spring Lake firefighters at least 20 minutes to extricate Freed and 45 minutes to cut Puckett from her smashed vehicle. They were assisted by Fruitport firefighters.