Ross's Goose, Chen rossii
	Ross's Geese are similar to Snow Geese, and in most places, much less common. However Merced NWR in the California Central Valley is the great wintering spot for Ross's, and they are more common there. Ross's are smaller, with a proportionately smaller bill, and a more rounded head, with an angle between forehead and bill, where on a Snow Goose there would be a triangular wedge of head and bill together. The Snow Goose also shows a dark line -- the "grinning patch" -- between the mandibles of the bill.
This flock looks to have been mostly Ross's, with some Snow.The great sight at Merced is the "blast-off" of thousands of geese at once. Here's a glimpse, but no photograph can do it justice.