The Golden Gate Raptor Observatory, is a nonprofit program of the Golden Gate National Parks Conservancy in cooperation with the National Park Service (NPS). GGRO volunteers have been tabulating the annual fall migration of birds of prey over the Marin Headlands. This migration—the most significant of its kind in the western United States—soars over Hawk Hill in the southern Headlands, a critical place from which to monitor eagles, vultures, falcons, hawks, and kites of more than 19 species, and to track long-term changes in their populations.