She worked for the American Museum of Natural history and co-authored the classic "Field Guide to Wildflowers of North America," with Roger Tory Peterson. Margaret McKenny was an expert on mushrooms, and wrote 15 books on that subject. In 1993, the elementary School located at 3250 Morse-Merryman Rd SE, in Olympia was named the Margaret McKennny Elementary. Also named for her is the State owned Margaret McKenny campground located in Capitol Forest on the banks of Waddell Creek (a 1930's gold panning creek). On January 13, 2009, the City of Olympia created the Margaret McKenny Park.