If we're just gonna start counting whether or not our waterways have access to the ocean, then pretty much every Midwestern state counts by way of the Mississippi's drainage basin. 32 states have tributary rivers that find their way to the Mississippi, and then to the Gulf.

Incidentally, I love the detail in this map where the state of Mississippi no longer touches the Mississippi River, and the city of New Orleans is apparently divided across the states of Iowa, Missouri, Illinois, and Arkansas.