Bison Impacts and Monitoring. Why monitor the bison? The House Rock bison herd on the Kaibab Plateau that migrated onto the North Rim of Grand Canyon National Park has adapted to various habitats; grazing and wallowing in park meadows, stampeding through dense forests, and occasionally venturing along the rim of the canyon. Concerns of ecological impacts and effects to archeological sites have increased over the years as these bison have begun to congregate around natural water sources and change their migration behaviors to stay within park boundaries for longer periods throughout the year. Park researchers and collaborators have been monitoring the impacts of this herd on the natural and cultural resources of the North Rim and are establishing a feasible reduction plan. Bison Impacts and Monitoring (U.S. National Park Service)