With tourism more vital to the economy, environmentalism also rose in importance. The Alaska National Interest Lands Conservation Act (ANILCA) of 1980 added 53.7 million acres (217,000 km²) to the National Wildlife Refuge system, parts of 25 rivers to the National Wild and Scenic Rivers system, 3.3 million acres (13,000 km²) to National Forest lands, and 43.6 million acres (176,000 km²) to National Park land. Because of the Act, Alaska now contains two-thirds of all American national parklands. Today, more than half of Alaskan land is owned by the Federal Government.