In addition to the topo maps, a browse through the Custom Maps directory will bring up lots of other specialty maps and data, like trails, POIs, and even raster maps for a few areas like Joshua Tree National Park. While the official Garmin 1:24K topo maps have more features, like elevation profiles, routing, and shading in supported units, much more of the US is covered by these free maps than is currently available from Garmin. Part of the reason for this flurry of activity may be that Dan Bloomberg, webmaster for the site and creator of most of the older maps, has released a new tool called Topo Process that simplifies the process of obtaining and processing the data necessary to create these topo maps. Windows installers available for all, Mac for many.
Since my last update on free 1:24K-equivalent topo maps for Garmin GPS units from GPSFileDepot, there’s been a huge explosion in the number of states covered: