Christopher and Kathleen Mask of Sedro Woolley were riding a Harley Davison eastbound on Cook Road when they stopped to make a left turn before 6 pm Saturday.
The Washington State Patrol says John Albrecht of Sedro Woolley failed to stop his car and struck the back of the motorcycle.
Kathleen Mask was killed and Christopher Mask injured.
Albrecht was booked into Skagit County Jail.
Troopers say drugs or alcohol were involved in the crash.