Outside St. Louis in Washington, MO, there is a course called Wolf Hollow. In the hot, humid summers, the nearby farms (not sure if cattle or perhaps small scale pig farms), occasionally lend that wonderful rural odor that just can't be compared. Also, a course closer in called Aberdeen has a hole that runs by part of a cow pasture that contains a lovely swamp - another great olfactory experience on a warm summer day.
On the east side, you have Gateway National. While it is close to a landfill, I have never been assaulted by the odors; however, you often get the sounds from the neighboring Gateway Raceway - be it stock cars, dragsters or what have you.
All are pretty good courses otherwise.
Steve