Possible Clues:

• Iowa native
• Iowan
• 'M*A*S*H' character
• Natty pathfinder
• Fictional Korean War surgeon Pierce (IA)
• New umpire — he covers a wicket that's important
• Resident of the Corn State
• Character in The Last of the Mohicans
• Natty Bumppo
• System that tracks path of ball in tennis, cricket etc