Margaret Murie, American environmentalist and author (died 2003)

Margaret Elizabeth Thomas "Mardy" Murie was a naturalist, writer, adventurer, and conservationist. Dubbed the "Grandmother of the Conservation Movement" by both the Sierra Club and the Wilderness Society, she helped in the passage of the Wilderness Act, and was instrumental in creating the Arctic National Wildlife Refuge. She was the recipient of the Audubon Medal, the John Muir Award, and the Presidential Medal of Freedom—the highest civilian honor awarded by the United States.

August 18 is the 230th day of the year in the Gregorian calendar; 135 days remain until the end of the year.