Possible Clues:

• Medium embodies such a psychic state
• With 24-Across, why a Midwest river has so many tributaries?
• Girl, our one, in a state
• Avoid our island in river in this state
• Girl nymph loses her head in part of 13 across
• State of central USA
• Jefferson City is the capital of this central US state
• Biggest tributary of the Mississippi
• Major U.S. river
• ___ Valley Conference in college sports