Why are you posting on the Whatcom county, Washington board?
It looks like he is buried in Monroe, County New York, so you could post on that board, as there may be relatives there. https://familysearch.org/ark:/61903/1:1:QVVW-HMHH
There is a New York newspaper site, that is free to searchhttp://www.fultonhistory.com/Fulton.html
ROCHESTOR DEMOCRAT AND CHRONICLE FEBRUARY 22, 1922
EDWIN R QUINBY DEAD
Brother of former comptroller, was captain in engineer corps
Edwin Rufus Quinby, captain of the engineer corps of the United States army, and son of the late General Isaac F. and Elizabeth Quinby, of this city, died on Monday in New York. Captain Quinby was a brother of former city comptroller, Henry D. Quinby, and Captain John G. Quinby, of the United States Navy. The body will be buried in Mount Hope Cemetery after services at Mount Hope Chapel at 10 o'clock this morning.
You will probably have to order his death certificate for cause of death.