Paul,
To load additional, detailed map data, you'll have to buy additional software from Garmin or one of it's dealers. (Authorized dealers are generally way cheaper than Garmin direct.) City Select is Garmin's "good" map set and contains most roads, including rural roads. City Navigator is Garmin's best map set, but it won't load on your Legend. Or you could buy software to run on your laptop and feed GPS data from the Legend.
For more info you can check out Garmin's
Legend C page or
gpsinformation.netStay safe,
JImJr