Not sure of your nav expertise (no disrespect is intended), but think of this as a good oppt'y to practice some map skills.
Using your map, plot your own GPS coord (UTM, lat/long, etc. - pick your pref) of known, fixed locations (e.g., top of DC). Once you have those points - check them against a reliable source. You'll get your coords and get some practice.
The coords can help but they won't do much to help w/routefinding.