This tutorial will direct you to download DEM data for the US:<p><a href="http:&#x2F;&#x2F;www.gpsfiledepot.com&#x2F;tutorials&#x2F;how-to-create-garmin-topo-maps---part-2---elevation-data&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.gpsfiledepot.com&#x2F;tutorials&#x2F;how-to-create-garmin-t...</a><p>The map viewer you use:<p><a href="http:&#x2F;&#x2F;viewer.nationalmap.gov&#x2F;viewer&#x2F;" rel="nofollow">http:&#x2F;&#x2F;viewer.nationalmap.gov&#x2F;viewer&#x2F;</a><p>Info about the elevation data you get:<p><a href="http:&#x2F;&#x2F;nationalmap.gov&#x2F;3DEP&#x2F;3dep_prodserv.html" rel="nofollow">http:&#x2F;&#x2F;nationalmap.gov&#x2F;3DEP&#x2F;3dep_prodserv.html</a><p>The data is kind of buried, but I went through this process for building maps and it appears to be very high quality.