Click on the link below to hear Scott Richmond's interview of Rob Crandall on the Clackamas River. (MP3 format 8:20 long.) Scott Richmond is the founder of http://www.westfly.com/ . Scott gets some good info from Clackamas river guide and editor of Flyfishing & Tying Journal, Rob Crandall.
Once you have clicked through to the page there is a gray bar with a play button. Press the play button to hear the interview (it may take a few seconds to load).
Good luck on the water!