How much land has Congress designated as wilderness

How much land has Congress designated as wilderness since passage of the Wilderness Act 40 years ago?

—Maureen Langloss, New York, NY

When Congress passed the Wilderness Act in 1964, it designated 9.1 million acres across the United States permanently off limits to development. Since then, lawmakers have added an additional 96.5 million acres—including more than 50 million acres in Alaska alone—or a total of 105.6 million acres, spread over some 662 different areas and constituting roughly five percent of total U.S. land mass.

Only Congress has the power to designate lands as federally protected wilderness. Typically, parcels of land need to be 5,000 acres or larger to be included. The Bureau of Land Management, the U.S. Fish and Wildlife Service, the U.S. Forest Service and the National Park Service each oversee different areas of wilderness within their respective holdings.

It was a group of influential policymakers, scientists and outdoorsmen that banded together in the mid-1930s whose advocacy work ultimately led to the passage of the Wilderness act 30 years later. Calling themselves the Wilderness Society, they included: Benton Mackaye, known as “father of the Appalachian Trail”; Robert Sterling Yard, at the time a National Park Service publicist; visionary ecologist and author Aldo Leopold; and Robert Marshall, then chief of recreation and lands for the Forest Service. Today the Wilderness Society is thriving, with a quarter million dues-paying members and wilderness preservation campaigns running from Alaska to Florida.

Despite protections provided by the 1964 law, wilderness areas face many threats today. Excessive human recreational activity takes a toll, as do air and water pollution from sources that originate outside wilderness boundaries. Non-native plants and animals that have been introduced over time threaten the native species that have evolved over thousands of years. Wildlife habitat in adjacent “buffer zones” is shrinking as development moves closer and closer to the boundaries of these wild lands. And ill-advised land management practices—such as widespread fire suppression—disrupt naturally functioning ecological systems.

This year, numerous government agencies and non-profit organizations are celebrating the 40th anniversary of the passage of the Wilderness Act and assessing how to best work together to protect wilderness lands in perpetuity. Conferences are exploring the important role wilderness plays in the American psyche, and “walks for wilderness” are scheduled on weekends this fall from coast-to-coast to raise public awareness about the role wilderness plays in the quality of life and the health of our environment. To find an event near you, log on to

CONTACTS: Wilderness Act of 1964,; Bureau of Land Management,; U.S. Fish and Wildlife Service,; U.S. Forest Service,; National Park Service,; Wilderness Society, (800) 843-9453,;,