TRACECAT Case Directory
Category 6, Physical Traces
Preliminary Rating: 5
Sept. 13, 1966; Stirum, ND (BBU 10944)
7:30 a.m. Rotenberger, 11, saw a silvery-grey elliptical [or disk shaped] object with a clear bubble dome on top, tripod landing gear, 2 red lights, 2 white lights, 1 green light, hover about 1 mile away, then land within 900 ft making a low-pitched whine and taking off so fast it just "vanished." USAF Lt. Col. and a Gwinner, ND, businessman investigated, found compact landing indentations 7 inches deep and radiation level 100 micro roentgens/hr (5-10x background level). (Berliner; cf. Vallée Magonia 797)
Not sure where the "5-10x background level" came from (I didn't see that in the docs) but normally that would be considered significant (2.5x is considered significant). The "0.1 milliroentgen" reading by Quintanilla's team implies a 4-times normal background compared to my area in Indiana, but not sure what normal is for North Dakota. A reading of 0.5 mr/hr is 300 counts per minute, so 0.1 would have been 60 cpm.
Detailed reports and documents
1966_09_13_US_ND_Gwinner_BB_CE2.pdf (Barry Greenwood & Jan Aldrich)