>From Russell Rogers, Seattle WA, rrogers at halcyon.com

It just so happens that I am currently collecting data on Snow Buntings.
Without question the record for the largest flock ever observed of this
species occured on 19 February 1972 when Jim Acton of Spokane saw an
estimated 15,000 to 20,000 at Reardan in Lincoln County (see American
Birds 26:633). That record was exceptional. Although I am not quite
finished going through all of the data yet, in eastern Washington there
are records of flocks numbering into the thousands, but most reports are
under 100. In western Washington, the highest count that I have come
across is from 1 December 1973 when 225 were seen at the Lummi Flats near
Bellingham (AB 28:684)

A flock of 2000 must be an impressive sight. Congratulations!