Hi Rhonda. It looks like your Avalanche is probably a 1988 model, based on the location and type of rear brakes it is equipped with. As stated above, location and condition of the drivetrain is a big factor in its worth.
Tig welded in Japan, double butted Tange, deore drivetrain, looks to be intact and in fairly decent condition. I'm not on the west coast, but I think you could get somewhere from $300 to maybe $450 if you are really lucky
1988 because of colour scheme. decent condition. as above said. might get as much as $300cdn in your neck of the woods.
down in vancouver up to $400. good luck with the sale