While legislation such as the Wilderness Act of 1964, the Clean Water Act and the Endangered Species Act of 1973 are embedded in many Americans' idea of government responsibility for the environment, these laws are being revisited.

CNN: Challenges ahead for a changing Earth

On her honeymoon, she and husband Olaus Murie (a scientist with the U.S. Biological Survey who later helped write and enact the Wilderness Act) traveled by steamship and then by dog sled through the Brooks Range, in winter.

NPR: Mardy Murie, Alaska's Passionate Protector

Olaus Murie died three years later, just before Congress passed the landmark Wilderness Act.

NPR: Mardy Murie, Alaska's Passionate Protector

Last week, she testified on Capitol Hill on behalf of Northern Rockies Ecosystem Protection Act or NREPA. If adopted, it would become the second largest wilderness expansion in U.S. history.

NPR: Rocky Mountain Activist Carole King