Starting today, the Iowa DOT is offering “complimentary vehicular/passenger ferry service” across the Mississippi River from Sabula to Savanna. This would last at least through the summer because of the delays in construction of the overflow bridge. There’s also a transit service.
There is one other car ferry service in Iowa: A seasonal $15 ride from Cassville WI to Millville across a narrow part of the Mississippi, south of where the Turkey River flows into it. That’s about halfway between Dubuque and Marquette. It doesn’t get much publicity though, aside from its inclusion on the map.
UPDATE: Story and video from WQAD.