Earth Resources Observation and Science (EROS) Center is a remotely sensed data management, systems development, and research field center for the U.S. Geological Survey's. Climate and Land Use Change Mission Area (link is external). The USGS is a bureau of the U.S. Department of the Interior. EROS opened in the early 1970's with a handful of employees and the largest mainframe computer in the State of South Dakota. It currently houses one of the largest computer complexes in the Department of the Interior. EROS has approximately 600 government and contractor employees.