America’s landmark Wilderness Act turns 50 this week. Signed in 1964 by President Lyndon B. Johnson, the law enables the government to set aside certain areas for preservation and protection. About 5 percent of land in the United States -- nearly 110 million acres -- is considered “wilderness,” encompassing everything from deserts, tundras and canyons to sand dunes, swamps and savannahs.

“A wilderness, in contrast with those areas where man and his works dominate the landscape, is hereby recognized as an area where the earth and its community of life are untrammeled by man, where man himself is a visitor who does not remain,” the act says. In practical terms, that means no vehicles, motorbikes or bicycles and as little construction as possible. Wilderness areas must span at least 5,000 acres and boast opportunities for “unconfined recreation.”

The National Wilderness Preservation System includes about 760 areas peppered throughout 44 states and Puerto Rico. Here’s a glimpse of 10 of them. (Captions draw details from, a collaboration of federal and university research programs.)