The County oversees two world-class museums, the Museum of Art and the Natural History Museum. The Art Museum is the premier encyclopedia museum in the Western United States, with more than 100,000 works of art, and serves 1 million visitors a year. The Broad Contemporary Art Museum was added in 2008. The Natural History Museum, the largest natural and historical museum in the Western United States, safeguards more than 35 million specimens and artifacts covering 4.5 billion years.The Natural History Museum Family includes the Page Museum and William S. Hart Ranch and Museum. The Page Museum, located at the Rancho La Brea Tar Pits, is one of the world's most famous fossil localities, recognized for having the largest and most diverse assemblage of extinct Ice Age plants and animals in the world. The William S. Hart Ranch and Museum contains original furnishings, an impressive collection of western art, and mementos of early Hollywood and Native American artifacts. In addition to the public facilities, there are more than 300 private museums in the County.