Ann Arbor / Dexter-Hillsdale Wave — USAF Swamp Gas Controversy
Over two nights in Michigan, approximately 100 witnesses including county sheriffs' deputies and a civil defense director observed disc-shaped craft at low altitude. USAF Project Blue Book sent Dr. J. Allen Hynek to investigate. Hynek's official explanation — 'swamp gas' — caused national ridicule and congressional outrage, directly triggering the Condon Committee investigation and Congressman Gerald Ford's formal congressional inquiry.