well i have never fished the ohio river, but the colorado river should be no diffeent. when we fish there, especially the main river channel, you should look for eddies or calm areas that are protected from the faster moving water. this is where bass will set up to ambush what ever comes by. second if you can find backwater lakes, those should have fish. in river systems, bass are almost always structure oriented so the best way to go after them would be a spinnerbait and a pitch bait. flipping should get you some bites and make sure to use a 1 ounce weight to fight the current.