1966 Washington Quarter. Is This A Retained Die Break?

It might be... can you do anything about the sharpness so we can see it better?

to the CFF!

hopefully these are better

is the area raised? almost seems like a piece of metal foil, hard to tell from the pictures

http://www.error-ref.com/?s=metal+foil

First,

It helps us to see what you are seeing if you could post:
one clear photo of the entire obverse
one clear photo of the entire reverse
a clear closeup of the feature that caught your eye

One easy way to get clear photos is to place the coin on a dark background, stack 2-3 books next to the coin, and sit a cell phone overhanging the books. The camera can be focused so the coin fills the frame. The photo doesn't need to be high resolution to capture the surface.

One thing I noticed with your coin was the "notch" on the rim between the second "S" of STATES and the "O" from OF. This suggests that something damaged the coin, producing the line that you see. The line also forms a fairly sharp "V" on the coin. A die break would be raised on the coin, rather than incuse (recessed), and would be more rounded and ragged. I suspect that your coin was damaged.

Again, welcome! Keep hunting, and keep asking questions!

Thank you all for the the help.