I found four white geese in Two Harbors this morning. I suspected the really white goose with a stubbier beak was a Ross’s Goose, which turned out to be correct. While on first glance the birds appear identical, pay particular attention to the beak which has a different shape. A Snow Goose’s bill also has a “grin” to it.
Here is today’s Ross’s Goose, and a better photograph from a few days ago of some Snow Geese. The Ross is almost a bit smaller and stockier. The “South Dakota Birder” has a great page focused upon identification.