black triangle flew silently overhead at tree top level

This report is for the purpose of authenticating a previous report filed for the date 6-15-1983, in the area of Redwing, MN.  I found this site some time ago and when I found it had reports dating back many years, I decided to see if anyone else reported what I saw many years ago.  Much to my surprise, I did.
In the early summer of 1983, I was 11 years old, my girlfriend and I were having a sleepover at her house in St. Paul Park, MN.  After a few hours of fun running around the neighborhood late at night, we settled down for bed in the back of her fathers pick-up truck, which was parked in the drive way (no topper on truck).
As we lay there talking and looking up at the sky, a very large black triangle, silently passed over us.  It had no lights on that I could discern.  It moved at what I would guess to be 10-15 mph.  It was just above tree top level. It created no wind.  It was very unnatural in its behavior.  Even though I was 11 years old, I knew this was not some normal aircraft.  My friend and I became very quiet and went right to bed after that.
I told my family. They did not believe me at the time.  I have shared this with many people over the years including my husband, who heard this from me long before I ever found this site.  Needless to say I was excited when I found out someone else saw the very same thing I did (validation).  I feel confident it must have been the same night.   Redwing , MN is just south of St. Paul Park.
My little school friend and I never really talked about what we saw at the time, but many years later, when we were adults, I tried to talk to her about it because I could never forget about it.  She said she didn’t remember it at all and acted as if I was strange.  I know she saw it at the time because it was frightening.
Witness indicates that date is approximate.  PD