September 1 — Martha, the last Passenger Pigeon, Died (1914)
September 2 — President Roosevelt Dedicated Great Smoky National Park (1940)
September 3 — Wilderness Act passed (1964)
September 4 — Fort Bragg, Home of Red-cockaded Woodpeckers, Established (1918)
September 5 — UNESCO Established First World Heritage Sites (1978)
September 6 — Alcide d’Orbigny, French Naturalist, Born (1802)
September 7 — Edward Birge, Father of Limnology, Born(1851)
September 8 — UN Millennium Declaration ratified (2000)
September 9 — First “Bug” Found in Computer (1945)
September 10 — Henry Hardtner, Father of Southern Forestry, Born (1870)
September 11 — World Wildlife Fund Began Operations (1961)
September 12 — Canyonlands National Park Established (1964)
September 13 — Walter Reed born (1851)
September 14 — Marc Reisner, Author of Cadillac Desert, Born (1948)
September 15 — Darwin reaches the Galapagos Islands (1835)
September 16 — Ed Begley Jr., Environmental Advocate, Born (1949)
September 17 — Edgar Wayburn, Wilderness Advocate, Born (1906)
September 18 — Grey Owl, Pioneering Conservationist in Canada, Born (1888)
September 19 — Urmas Tartes, Estonian Nature Photographer, Born (1963)
September 20 — AAAS Founded (1848)
September 21 — Assateague Island National Seashore Created (1965)
September 22 — Peace Corps Becomes Law (1961)
September 23 — Rose Selected as U.S. National Flower (1986)
September 24 — President Kennedy Dedicated Pinchot Institute (1963)
September 25 — Pope Francis Addressed the UN on the Environment (2015)
September 26 — Johnny Appleseed Born (1774)
September 27 — “Silent Spring” Published (1962)
September 28 — National Public Lands Day