Our pink snow is alive.
It owes its hue to a certain microscopic algae, Chlamydomonas nivalis, often mixed
up with the pollen from whitebark pine. The pink -- also called
watermelon -- snow owes its color to a pigment not unlike that found in
either flamingos or tomatoes, not to be confused with the red snow caused by dust storms. The top pink snow resource on the Web (complete with some great pics of the stuff from California's High Sierra) is at Wayne's Word.
The Straight Dope offers an alternative possible cause for the coloration:
Another theory, from an eminently reputable source, "The Cat in The Hat Comes Back" by Dr. Seuss, describes pink snow resulting from a desperate attempt to remove cake frosting from the bathtub, then mother's dress, then the wall, father's shoes, the rug, the bed, and finally leaving the snow all around the house pink. To turn pink snow white again, you need VOOM, carried in the hat of Little Cat Z.
Just be thankful the high country's
summer snow is not infested with snow worms or -- the horror! -- snow fleas.
