I have done the section from Leatherwood Ford to Blue Heron in a weekend trip. It was about 18 or 19 miles with only a couple major rapids at the end. Both of those (big shoals, devils jump) are pretty dangerous under high water on the first part of the year around spring. We done it in June and still had to rope off the canoe and let it float through instead of portage.
Camping was primitive and in that stretch there are no major roads or people only woods with logging trails.
It was a very peaceful largemouth and smallmouth filled trip for us. A 6 pound smallie is in there and may have friends but you will catch them in the 15 to 20 inch range more often. It is also full of walleye and sauger. The water is clear, deep and usually cold. When you start heading into the gorge there will be boulders the size of a garage under you and just vanish in the depths. But that makes for a nice shot when a 20 inch smallie is coming up from deep to hit you jig and can watch the whole thing. We used hair jigs (3/8 ounce and smaller in brown, olive, black). There are trout in some of the creeks that feed the main river but you will need a KY license for it. As long as you fish the main river you can use the TN license.
Also for what it is worth the Scenic River Railroad was a waste of money for what you got out of it.
