I estimated over 4,000 Snow / Ross's Geese were seen at the Merced NWR. While they mixed in the water, the roost sites seem to be broadly segregated by species. There were several levees and islands like this one that were nearly white with white geese, although this flock also includes a smattering of Greater White-fronted Geese.

A complete list of birds seen this day can be found here:

http://ebird.org/ebird/view/checklist/S34968126