I have created one for use on a Garmin nuvi 250W based on digital topographic maps and a partial list of Algonquin campsites from
http://mapcenter.cgpsmapper.com/ but
would be interested in other attempts. The sites list locations were quite inaccurate so I have corrected them using Jeff McMurtry's map - although Jeff indicates they are one of the least accurate aspects of his map. In addition, the treatment of water and marsh can be substantially different on topographic and canoeing maps ie. where one can walk vs. where one can paddle. But generally it looks OK.
The 250W nuvi is for automobile use and does not provide track or route capability but it will show current position and also predetermined locations can be saved and used for guidance. It has an excellent bright display but is not weather proof so it has to be "babied" (like most cameras). I have no idea whether the display would be identical on other mapping GPSrs.
