Some maps have the capability to upload/download waypoints,  routes, and tracks to SOME GPSRs.  If <for instance> Delorme maps are listed as having this capability with Garmin or Magellan GPS receivers,  this does NOT mean compatibility with ALL of that manufacturer's products.  ASK specifically about YOUR GPS receiver BEFORE you buy.  Lowrance does not offer TOPO maps for their consumer model GPSRs.

TOPO Map Downloadability:
1) NO maps not furnished by the GPS manufacturer can be downloaded into ANY consumer model GPS receiver.
2) Garmin TOPO maps can be downloaded into all of Garmin's Mapping Receivers (ONLY).
3) Magellan TOPO maps can be downloaded into the M-330,  and Meridian line ONLY at this time.
4) These TOPO Maps are for reference and do not interface with a GPS receiver.
5) These TOPO maps can be run in a PC and linked to a GPS receiver to allow plotting of your position on your PC.

Compatibility:  (a) Garmin,  (b) Magellan, (c) Lowrance and (d) None

Delorme Maps provides TOPO maps for the United States that run on your PC (a,b,c, 5)

Maptech Terrain Navigator 3-D maps of the United States that run on your PC (a,b,5)

USGS DRG individual 1:24,000 topo 7 1/2' Quad maps, low cost.  Use with Ozi Explorer (a,b,c,5)

Garmin TOPO Maps for the United States can be downloaded into your Garmin GPS.(1,2,,5)

TopoZone.com  provides Interactive TOPO maps for the United States.(d)
 

If you have additional TOPO maps that would be appropriate to add to this listing,  PLEASE email JOE