Maybe someone can help me out here. I heard that SD has downloadable apps for GPS units. IS this something the DNR has on thier site or is it something I need to purchase over the counter? What I've heard is you can pick a county and dounload its map(s) right into a GPS. I havnt looked at the SD web site yet so I dont know if its found there or where/what. Can anyone point a guy in the right direction?