The directions for loading the maps, and the links to the maps I use came from here:
http://www.gpsfiledepot.com/tutorials/h ... -gps-unit/They vary from state-to-state, but for Utah they are very detailed and accurate. Most, if not all, of the roads and trails we took last year were already on this map set. Here is a link to the Utah map.
http://www.miscjunk.org/mj/mp_uttopo.htmlThe maps I created were done in the Garmin MapSource software using these Utah maps and the actual track data from our trips.
The California map set is also very good and very detailed.
These maps are public domain.
The Nuvi's, from what I have seen, are more of a "route" GPS than a "track" GPS. The "route" is more like a head's up display, with a turn by turn, looking forward, view. The "track" is an overhead view. I prefer the "track" way of navigating. It leaves or follows "breadcrumbs" and is more natural for me in an off-road situation. It is also what is used by Desert Racers on their Lowrance Baja series GPS', so that is what I need to work on the KOH courses. My GPS is a Garmin 60CSX.
I can send you the "track" data from last year's trip. You may be able to put that on the Nuvi, or convert it to a "route". I do not know. Maybe the Nuvi's can also be used in a 'track" format display?