Find an important year listed at the site. Divide that number by 1.9, round off the decimals and add this to your latitude (North) coordinate. Take that same year, divide by 1.12, round off the decimals and add this to your longitude (West) coordinate. (Treat the coordinates as one big number, forget the direction and degree. So N45*31.944 becomes 4,531,944 and W94*05.804 becomes 9,405,805.)
You will now have a new set of coordinates and the location of the cache. Your quest should take you past the longest uninterrupted granite wall in the world (MCF-Saint Cloud) via the shortest state hiway in MN (MN 301).
You can check your answers for this puzzle on Geochecker.com.