I've become a big Salmon River fan, since discovering the great steelie possibilties over there. Been trying to learn all I can, as it's a 6 hour trip for me, and it's nice to hit it right. I prefer the water level to be 335-700cfm, don't like deep wading in 34 deg. water! As far as ideal conditions, well, whenever the fish haven't been harrassed too heavily for days on end, and it's not too dam cold to get out and fish. Tomorrow would be a good day, IMHO, as it's been too cold for the past week for the troops to be dragging the slinkies through all the good pools, and it's supposed to be "warm" (30 degrees). I recently heard an old duffer claim that the steelies will go on the bite when the barometer rises sharply... I don't think there's any way to plan a trip based on optimal conditions any further ahead than 4-5 days, unless you're a fan of the Farmers Amanac. But all that said, I'm certainly no expert! Just an enthusiastic student.
I'd suggest contacting Andrew at Tight Lines Flyshop, a new board sponsor. He's very knowledgable about the Salmon River- he's given me some solid advice on the SR. <http://www.tightlinesflyfishing.com/
There are a few other sites with good info, but I'd probably get smacked for posting them here, so email me, and I'd be happy to pass 'em on.
macspey aka john