It wasn't so much what I saw but how it moved that I will never forget.

I was a young girl of twelve or thirteen and my family & I were taking a drive through a seminary that was open to the public.  St. Mary’s of the lake in Lake County, IL.  We would take drives during the fall to look at the flowers & foliage of this beautiful place that had scenic drives over brick bridges surrounded by large trees.
I was looking out the side window from the backseat of the automobile.  I was a very observant young person (I still am today) as I loved nature and would spend hours gazing and looking for any and all signs of wildlife.
Suddenly above the tree line to my right I saw an object rise up from the trees.  It was disk shaped and eggshell color with what appeared to be small windows running circular on the upper portion of the saucer.  So there was an upper small section as well as the larger disk on the bottom.
What caught my eye and will remain with me is the way this object moved.  It sort of floated up at a 45-degree angle and hovered for a second or two before descending back to earth at the same degree and speed.  I had never before seen or have since seen anything move the way this saucer moved.
I told my parents and they believed me and we actually went looking for it.  However, it was difficult to gauge exactly where this was in proportion to where we were at the time.  Years later I saw this same saucer shape depicted in a small-scale model at the store that was built based upon a description from a lieutenant in the U.S. armed forces.  I wish I had purchased that model.
Witness indicates that date is approximate.  PD