Yellowish/Orange object seen in early 70's SW Michigan.

My friend and I were walking west on a private road, when I noticed a lighted object in the sky to the North approx. 2 miles away.  This object was a dull yellowish/orange in color and was just above treetop level, maybe 100 ft.
We both were in awe of this sighting,the objects shape was a parallelogram that tumbled in its movement from west to due east.  We knew from the shape and movement that this was something really different.  As it moved out of our eyesight a motorcycle was heading towards us (we still were walking west)the motorcycle stopped and the rider asked if we had seen what he also witnessed.  It so happens my friend knew this guy and he was really excited(as were we) he was driving home from 3-11 shift and noticed it.
He was heading south and  he stopped on the side of the road to watch it.  When it passed over him it caused his motorcycle to stall out.  It made absolutely no sound as it tumbled over him as it moved due east.  
Since this happened years ago I wanted it to be known 1 witness besides me still lives in the area (motorcycle rider).  
I have 2 other sightings to relate if interested 1 involving light shafts (scanning?)
Witness indicates that the date of the event is approximate.  PD