Beneath this valley lies one of the richest fossil deposits in the world, and in 1969 its future was threatened by proposed housing development on privately owned land. Concerned citizens and scientists formed the Defenders of Florissant to seek federal protection for the Florissant fossils. In court, Victor J. Yannacone, jr., joined by attorney and future Colorado Governor Dick Lamm and Tom Lamm, pursued a legal strategy that won an injunction stopping development of the valley and helped set precedents in environmental law. Their efforts, along with the temporary delay they secured, gave Congress time to pass the bill establishing Florissant Fossil Beds National Monument, which President Nixon signed into law on August 20, 1969.