Here's the reg:

OHIO RIVER FISHING
(KRS 150.170)
An angler with a Kentucky fishing license may fish the entire main stem of the Ohio River from a boat, or a bordering state’s bank without buying the other state’s license (bordering states include Illinois, Indiana and Ohio). This does not apply if fishing a bordering state’s embayments or tributaries, which begin at a straight line between opposite points where the tributary or embayment meets the main stem of the river.

http://fw.ky.gov/pdf/08fishboat2.pdf

That's a downloadable pdf file, worth saving.

Good Luck!