Mongo-
Certainly this is not the first time you have encountered such an alien substance. I live here in Hell "A" and make the occasional trip up to Duke Nukem's Cafe there in the Angeles Crest/Angeles Forest and its not uncommon at all to get into a rather descent amount of snow cover. There is a nice little jaunt called Nine Mile out there that I like to ride... or is it Seven Mile - I think it's Nine Mile. Though in looking at your 50 mile route I think I might like to give that a shot. I know that around Lake Castiac snow is the least of your worries cause the wind can get pretty vicious up there.
Nonetheless, whenever I head up there anytime past late November I usually dress for the cold and steady my self for the white stuff.
Just remember that its pretty harmless stuff - It's even edible, but not the yellow kind.
The Big B