My Wife and I ride ATVs in the vast uninhabited areas of Calif,Ariz & Nev.,on logging roads ,gold mine access roads, desert washes etc. You could get LOST very fast out there if you did not have a good GPSr mounted to the ATV. I have both the S&D and TOPO but only use the ToPo for our outback ventures.I find that the detail is amazing when it comes to knowing where you are, which fork in the road/4wd trail, which side of the stream to take and not get LOST. Great product, We would not go into the wild areas with out our Meri/Plat loaded with MapSend ToPo.