Alton A. Lindsey (May 7, 1907 – December 19, 1999) was a pioneering ecologist who was largely responsible for the creation of nature preserves in the state of Indiana, where he was a professor of forest ecology at Purdue University from 1947 to 1973. His book, “Natural Areas of Indiana and Their Preservation” (published 1970) was used to support the creation of Indiana’s first nature preserve, Pine Hills Nature Preserve, and he was also instrumental in the creation of the Indiana Dunes National Lakeshore. The Army Corps of Engineers plan to dam Big Walnut Creek in Indiana was also halted due to the efforts of Lindsey and a number of other activists; today there is also a large nature preserve along the Big Walnut.