AA does not serve YVR except via DFW (and possibly ORD). The departure of CP has really hurt their routes to this part of Canada. AS is supposed to be AA's partner on the west coast routes which it doesn't serve but there is no codesharing. Many routes especially intra-PNW ones were discontinued after the acquisition and integration of Reno Air.

Your best bet would be to watch fares from LAX-SEA (going to Canada adds at least US$50 mainly in U.S. customs fees). Keep an eye out on the WN and AS sites in addition to AA's. US$140 r/t would be a good fare.