The posted coordinates will bring you to a marker on the Illinois Prairie Path telling you who built the nearby bridge. Use the information on this marker to create an answer key that will be used for all seven of the "Bike The IPP" multi-caches.
Answer key:
Create a string of letters by selecting the first letter of each word/abbreviation
Number the first ten unique letters of this string 0-9
This cache can be found at:
N41 53.IIO W88 13.EOT