In the United States, the best open-to-the-public collection of trilobites is located in Hamburg, New York. Informally known as Penn Dixie, it was discovered in the 1970s by Dan Cooper. The shale quarry stopped mining in the 1960s, but the amount of rock turnover showed large deposits of trilobites. As a well-known rock collector, he incited scientific and public interest in the location. The fossils are dated to 350 million years ago when the Western New York Region was 30 degrees south of the equator and completely covered in water. The site was purchased from Vincent C. Bonerb by the Town of Hamburg with the cooperation of the Hamburg Natural History Society to protect the land from development. In 1994, the quarry became Penn Dixie Fossil Park & Nature Reserve when they received 501(c)3 status and was opened for visitation and collection of trilobite samples. The two most common found samples are "Phacops rana" and "Greenops".