https://en.wikipedia.org/wiki/Floyds_Fork
I have seen the Guyandotte river near where my wifes extended family lives. It is not much wider than Floyd's Fork running through Jefferson County/Louisville. It is however, a much deeper channel so it can carry more water volume before leaving its banks. There are only a few spots I know of on Floyd's Fork that is more than waste high unless in a flood condition where it leaves its banks quickly and doubles or triples in width. Floyd's fork is considered a creek around Louisville, while the Guyandotte is considered a river. What threshold has to be overcome to be called a river is somewhat arbitrary in my experience. But that is limited to Green, Salt, Red, Guyandotte and Ohio rivers. It probably has more to do with the acres 'drained' than its width and depth?
The Three rivers usually mentioned in the various versions of Swift Journals
https://en.wikipedia.org/wiki/Guyandotte_River
https://en.wikipedia.org/wiki/Kanawha_River
https://en.wikipedia.org/wiki/Big_Sandy_River_(Ohio_River_tributary)
and of interest...
https://en.wikipedia.org/wiki/Ohio_River
Consider how Swift and Co. crossed these rivers with mules and horses...and if they had a train of mules, the difficulty of that task. Finding historical fords on these rivers WILL show their path.