I let doubt. The list is not full on Wiki. There are nearly 17,000 freshwater lakes throughout the continental U.S. according to Garmin.
But anybody can try to check coverage for favourite lake:
http://www8.garmin.com/cgi-bin/mapgen/webmap.cgi?p=156172289&u=1&v=0&cp=4CB5D85AEDCFD85A&z=3&x=240&y=180&w=480&h=360&d=0&rz=0&k=1&sc=1