COTTAGE GROVE, Minn. - If you've ever used Mapquest, or plugged an address into your Garmin GPS unit, you've seen the work of Don and Amy. The two field analysts drive the highways, and the gravel roads way off the beaten path in the upper Midwest. They are digital mapmakers on the road for Navteq. M.A. Rosko takes us along to see how a new roundabout in Cottage Grove gets put on the map.