Riviere was on the wrong side of the road when the Toyota van she was driving collided with the ute on a bend at Nevis Bluff, on State Highway 6, on December 20, police said.
Saunders' ute crashed about 100 metres down a steep bank, ending partly submerged in the Kawarau River.
About 25 emergency services personnel attended the scene.
Police confirmed Saunders died at the scene. No one else was in his vehicle.
