Robert Marshall, Aldo Leopold and Howard Zahniser dedicated their lives to protect the shrinking American wilderness. As a result, the Wilderness Act passed in 1964.
Native Alaskans, oil company representatives, environmentalists, politicians, and others tell the story of the 800-mile pipeline.
President Theodore Roosevelt was caught in the middle of the first major battle for wilderness preservation in Yosemite National Park.
The journey of Prince Maximilian, German naturalist, and artist Karl Bodmer, who explored the Mississippi River area from 1832-1834.
Vivid memories of those trapped in the terrifying temblor of 1906 that killed thousands of Californians.
In 1934, American polar explorer Richard Byrd became the first to experience winter in Antarctica's interior.
The most daring and innovative accomplishment at the turn of the 20th century.
High on a granite cliff in South Dakota's Black Hills tower the huge carved faces of four American presidents: George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt.
When an earthen dam broke without warning, a small city in Pennsylvania was swept away in a wall of water over 30 feet high.