Milly Zantow pioneered the plastics recycling movement and invented the numbered-triangle system used for identifying different kinds of plastic.

Emma Toft is known as “Wisconsin’s First Lady of Conservation” for her efforts to save an ancient forest in Door County from being destroyed by logging and commercial development.

Estella Leopold was a paleobotanist and conservationist who conducted ground-breaking research on fossilized pollen.

Frances Hamerstrom, an ornithologist who helped save the prairie chicken population in Wisconsin, was the first woman in the U.S. to earn a master’s degree in wildlife management.