Narrower Terms (8)

• Big Blue River Valley (Ind.)
• Harden Hollow (Ind.)
• Kankakee River Valley (Ind. and Ill.)
• Maumee River Valley (Ind. and Ohio)
• Saint Joseph River Valley (Mich. and Ind.)
• Wabash River Valley
• White River Valley (Ind.)
• Whitewater Valley (Ind. and Ohio)