They explored and advocated for the protection of a range of aspects of Indiana's natural heritage, from birds and other wildlife to flowers and plants, including ferns. In many cases, they lived during eras (including the late 1800s and early 1900s) before the word "environmentalist" even was used. Some of them were called "conservationists".

They were often self-taught in our natural heritage, with true "in-field" experience. Even though Frank Wallace (1878-1968) didn't have a high school diploma, his expertise meant that he served as an Indiana state entomologist for more than 40 years. Jane Brooks Hine (1831-1916) of DeKalb County in northeastern Indiana became known as the "Bird Woman of Indiana" while documenting hundreds of sightings for the federal government. A former teacher and mother of six, she wrote for various publications and served on the Indiana Academy of Science.

During a later era, John Gottschalk (1912-1999), a native of Berne, Ind., rose to become a top federal official as director of the U.S. Fish and Wildlife Service. On a local level, Maurice McClue (1878-1957), who loved wildflowers, trees and wildlife, donated more than 80 acres of his family's farm to "the citizens of Steuben County" in an era before land trusts.