Generally speaking migrating fish run shallow, feeders run deeper. Feeders are predominately on Needle Fish close to the bottom. Migratory fish when they arrive inshore or in the surf line on the West Coast are usually shallow. I believe water temp. comes into play on migratory fish if they are running deep. I have seen times in Barkley Sound when fishing was dead only to find that the Chinooks had come in deep to arrive in Alberni Inlet. Current, water temp, and proximity to home stream will usually determine depth of mature migrating fish. Then again when you think you got it figured out the fish proves you wrong.
In keeping with this thread. Great story Rollie, have you been snatching any deer carcasses off the highway lately?