I'm sure the following study has been reviewed and discussed on this forum in the past: http://www.tn.gov/twra/fish/StreamRi...uction2006.pdf
From a quick glance, it looks like temperature on the Clinch during brown trout spawning season may be at least part of the issue. The report indicates that rainbow trout reproduction has been documented on the Clinch. I must admit, I kept wondering as I was reading this thread about the references to Rainbows spawning in the Spring. I realize there are many exceptions, but I was under the impression that brown trout generally spawned in the Fall, while Rainbows spawned in the Spring.