The apparent polar wander path for North America during the Late Cretaceous to Paleocene interval contains a deflection or cusp that may reflect a period of major plate reorganization. However, the resolution of the APW is insufficient to demonstrate that portions on either side of the cusp are small circle paths and that the cusp is a distinct break. This project will utilize several volcanic sequences of Late Cretaceous to Eocene age in Montana to refine, using standard paleomagnetic techniques, the North American Late Cretaceous apparent polar wander path. The work will be conducted in collaboration with researchers at the University of Montana.