I did some calling around, and this is what I found in Portland, Oregon. Of the handfull that I called, I found three establishments that will be participating this year:
HobbyTown USA
25699 SW Argyle Ave
Wilsonville, OR
503-685-7333
Opens at 10:00 a.m.
Guardian Games
302 SE 3rd Ave
Portland, OR
503-238-4000
Opens at 11:00 a.m.
Knightfall Games
9955 SW Beaverton-Hillsdale Highway
Beaverton, OR
Rainy Day Games
18105 SW Tualatin Valley Hwy
Beaverton, OR
503-642-4100
Opens at 10:00 a.m.
Not Participating:
Bridgetown Games
Empire Games
Gamers Guild
All other HobbyTown USA locations
Nexus Games
Most of the non-participating stores either (a) had never heard of Free RPG Day, or (b) didn't get the info in time to register. Maybe next year, the ship will be much tighter.