Wildlands once spread far and wide across the Earth. Today, only fragments of untrammeled lands remain. In North America, we find these lands mostly in wilderness. In 1964 Congress designated America’s first federal wilderness areas. Collectively, these areas are called the National Wilderness Preservation System. Between 1964 and 2004, the system has grown from 9 million acres (3,643,300 ha) to 106 million acres (42,898,200 ha) and contains 662 wilderness areas in 44 of 50 states. Overall, however, only about 5% of the entire United States—an area slightly larger than the state of California—is protected as wilderness. Because Alaska contains more than half of America’s wilderness, only about 2.5% of the contiguous United States—an area about the size of South Dakota—is protected as wilderness.