Can these yummy mollusk be bought anywhere? I never have time to go and do this. 
The Quinaults sell them. In Aberdeen and Hoquiam you can get them at Swansons, not sure about Safeway or Top Food. Swanson's usually has them for about 8 or 9 bucks a lb. if I remember right. I'll check them next time I'm there. I'm sure they must market them elsewhere too.
The ones from Alaska come from Poly Creek (the only certified commercial beach in Alaska), which is on the west side of Cook Inlet. Most of the crews that used dig there were from the Grays Harbor area. A gal from Ocean Shores used to run the crew there.