Only five records for Redhead at Marymoor, and none since 2002.  Bafflingly, all four seasons are represented with the five sightings, though typically Redhead are most common (though always rare) in winter in King County.

The sightings were: pair on the lake, 1995-05-23;  male in the slough, 1996-02-01;  male flying down the slough, 1997-11-27;  male on the lake, 2002-07-18, and a female in the slough, 2013-12-19