Ferries and steamships connected the Tri-Cities before the bridges were built. Here's one from 1909.

It was operating near the White Bluffs area. I wish I could have seen it in action. Instead of having the horses on the shore pull the ferry across, there appears to be a pulley system in the ferry and the horses on the ferry walk in a circle across the river! This is incredible. I've never seen anything like it in my life. Hold on a minute, I want to stare at the photo a little longer...