Complex sentence: Wilderness areas are covered by the US National Wilderness Preservation System, which protects federally managed lands that are of a pristine condition, established by the Wilderness Act (Public Law 88-577) in 1964.
Split into simpler sentences: Wilderness areas are covered by the US National Wilderness Preservation System, which protects federally managed lands that are of a pristine condition. Established by the Wilderness Act (Public Law 88-577) in 1964.