One sunny afternoon I saw a flat bottom thick gray disk slowly moving east observing this over a minute.

While sitting in my back yard, facing due west, reading a book, I looked up and slightly to the left I saw a light grayish silver object. It was the size of a 25 cent piece at arms length.  It was round like the quarter, flat bottom, rounded edges, thickness was about 1/4th the length of the object.  Movement was slow and wavering.  It was moving due east directly over Sheppard AFB.  I live six blocks from the Sheppard Missle Road North entrance gate. There was no noise, no trail, or other characteristics. The neighborhood and base noises were lacking.  I looked away and blinked my eyes in disbelief.  Looked again but the object was gone.
Witness indicates that date of incident is approximate.  PD