Triangulation
Triangulation is a method of finding your location based on the known location of landmarks. Using a compass, you find the direction between you and at least three landmarks visible from your location and marked on a map. You would then mark a line from each in the compass direction toward your location. The point where the three lines intersect is your location.
Why 3 points? Technically, you could get away with finding your location at two points. But often, when drawing that third line, you find that the three lines don't quite intersect perfectly, leaving you with a small triangle, which represents your error in estimation. Of course, more than three points will (hopefully) reduce that error even further, but generally, you find your location with enough precision to find your way to your destination.
The cache is not at the coordinates listed, rather you will have to triangulate its position using information about the landmarks below. You can solve this puzzle using a compass and a map, or you can use digital mapping software such as Google Earth or Garmin Basecamp to do the triangulation. There is also a mathematical solution using systems of linear equations. You'll likely find coordinates within a ballpark range. Use your geosenses on location to do the rest.
Moscow Mountain Summit - 43°
Tomer Butte - 114°
East Twin - 30°
West Twin - 26°
Friendship Square - 296°
GC57EAQ - 298°