August 4, 1965 — Calumet AFS, Mich.
Night. Radar operators at Calumet Air Force Station [now operated by Keweenaw County] near Phoenix, Michigan, track 7–10 objects in V-formation traveling from southwest to north-northeast at about 9,000 mph over Lake Superior. The same night, radar targets at Duluth, Minnesota, are chased by USAF jets. [Eberhart]
Sources:
“U.S. Airmen Say UFO ‘Formation’ on Radar,” Memphis (Tenn.) Press-Scimitar, August 5, 1965;
Flint (Mich.) Journal, August 5, 1965;
Minneapolis (Minn.) Star, August 5, 1965;
New York Post, August 5, 1965;
Register (Mich.), August 5, 1965; [Not sure what paper this is]
“Michigan Airman Spot UFO Formation,” Harrisburg (Penn.) Evening News, August 5, 1965, p. 3;
Brad Sparks, Blue Book Unknowns Catalogue, Case 1624, p. 306;
Center for UFO Studies, [case documents])
http://cufos.org/cases/1965_08_04_US_MI_Duluth-AFB_NICAP_MultiWit-Radar.pdf