HELENA, Mont. (AP) -- A 66-year-old Arizona man was killed and a 64-year-old woman was injured in a motorhome crash on U.S. Highway 89 near Corwin Springs, north of Yellowstone National Park. The Montana Highway Patrol says the motorhome was northbound Tuesday morning when a rock or another object struck the windshield and possibly hit the driver. The patrol says the man was injured and lost control of the motorhome, which went off the side of the road, collided with an embankment and rolled onto its left side. The man died at the scene. The woman was taken to the hospital in Livingston. Their names have not been released but the patrol says they are from Benson, Arizona. Officials are still investigating the cause of the man's death.