I don't know the fly fishing streams in that area very well but I would expect he will stay pretty close to Portland. Maybe the Deschutes, Wilson, Clackamas, Molalla, Trask, etc. Probably the rivers and streams west of Mt. Hood or the coastal streams in the mountains west of Portland. He doesn't have a boat so it would have to be something wadeable. Maybe I should also be asking what's close that would be good for a beginner.