Downloading “free” USGS topos from around the web?? Are you getting the new, enhanced USGS topos – US Topo? Chances are that if you’re downloading or even paying for free USGS topos from various, archaic data repositories and data warehouses (and depots) you may be grabbing older data. US Topo is the next generation of digital topographic maps from the U.S. Geological Survey. Arranged in the traditional 7.5-minute quadrangle format, digital US Topo maps are designed to look and feel like the traditional paper topographic maps for which the USGS is so well known. At the same time, US Topo maps provide modern technical advantages that support wider and faster public distribution and enable basic, on-screen geographic analysis for all users. Some facts and features of US Topo:
- US Topo users can turn geographic data layers on and off as needed
- zoom in and out to highlight specific features or see a broader context
- print the maps, in their entirety or in customized sections, on a wide variety of printing devices
- Additional analytical tools are available free for download.
- File size for each digital 7.5-minute quadrangle is about 15-20 megabytes.
- The prototype of US Topo, “Digital Map–Beta,” has been available since June 2009 and currently covers 17 states.
- US Topo maps include all of the content of the earlier “Digital Map–Beta,” plus integrated contours and hydrographic features.
For more information on US Top see this article for some great pointers