Sorry to flog a dead horse.......
I've been entering my past (1988 - 2000) weekly counts of Green Lake (King Co., Seattle, WA) into a spreadsheet in preparation for a long-overdue article (what's all the data worth sitting in a notebook on a shelf or on a hard drive somewhere where nobody has access to it?).

So:
First dates for Buffleheads on Green Lake (remember it's a weekly count so arrival dates are +/- 3.5 days.....
1988 : 10/25
(1989 - 1993 not entered yet)
1993: 10/13
1994: 11/02
1995: 10/25
1996: 10/23
1997: 10/15
1998: 11/04
1999: 10/27
2000: 10/25

For what it's worth.

Martin Muller, Seattle
martinmuller at msn.com<mailto:martinmuller at msn.com>
----- Original Message -----
From: JERRY D AND MARCENE D'ADDIO<mailto:jmdaddio at msn.com>
To: tweeters<mailto:tweeters at u.washington.edu>
Sent: Saturday, November 08, 2008 9:30 AM
Subject: [Tweeters] Buffleheads


Being a longtime commuter over the 520 bridge, I usually see Buffleheads settle in on Montlake in October and leave in April. They are not there yet, though I see Michael Hobbs had a flyby at Marymoor on Thursday. Are they late this year?
I recently returned from a 11 day car trip to and from the Southwest where I saw Buffleheads at Klamath Basin lakes. And Arizona birders are reporting them, too.
Marcy D'Addio
Redmond, WA