The case record
What was reported?
Numerous witnesses reported strange lights close to the ground; J. Allen Hynek's 'swamp gas' explanation became notorious.
The dates are bounds supplied by the workbook; they do not establish the exact day of an event.
- Reported date
- 20 Mar 1966 – 21 Mar 1966
- Witnesses
- Residents / students / police · Many
- Investigation
- Project Blue Book
Evidence in the record
Eyewitness testimony
Competing explanations
Official and research context
Swamp gas / marsh gas
Conventional explanations
Marsh gas and astronomical misidentification
Arguments that remain contested
Some reports may represent different stimuli
Locations & timeline
Coordinates are representative. Area and route labels do not imply exact paths or object positions.
- Primary reference location
Marsh areas near Dexter and Hillsdale
Dexter / Hillsdale
Reported event location · Approximate area radius: 30 km
42.330°, -83.880° · multipoint · Medium - Linked location
Dexter
Dexter, Michigan, USA
Witness cluster · Approximate area radius: 5 km
42.338°, -83.889° · area · High - Linked location
Hillsdale College / Hillsdale
Hillsdale, Michigan, USA
Witness cluster · Approximate area radius: 5 km
41.920°, -84.630° · area · High
Record notes
Create separate Dexter and Hillsdale markers.
Imported starting record; individual claims and source links await editorial verification.
Original dataset status: Partially explained / disputed