These are snow geese. The two with the white heads are know as Blue Morphs, the one in the center appears to be a juvenile. The more common is the White Morph which is all white with black wing tips. Females do not breed until they are 2-3 years old.
Went to Wagon Train and Stagecoach Lakes today with Kris. What a great day, nice to see the sunshine and the Pelicans.