USGS 7.5-minute quadrangle paper maps are being shoved aside. Digital US Topo maps now available on the Web perform like traditional paper topo maps while offering important technical advantages.
For more than a century now, the 7.5 minute quadrangle map, which has a scale of 1:24,000 (one inch to 2,000 feet), has been the standard map used by outdoor recreationists, scientists, land managers, and many others. The USGS has produced over 57,000 different ones since the agency was founded in 1879. Today you can obtain 7.5 minute quadrangles covering all 48 contiguous states, Hawaii, the U.S. territories, and the Anchorage, Fairbanks, and Prudhoe Bay areas of Alaska.
The problem with our old topographic maps is that they are, well…… old. As cultural features of the landscape have come and gone through the decades, and as orthophoto mapping, satellite imagery, GIS, and other remote sensing, refined mapping, and geoanalytical techniques have come into widespread use, USGS hasn’t had the money to update the paper topo map series. It’s been impractical to rely on volunteers to do the job, too. After a good deal of hand-wringing, it was finally decided that the paper topographic map series would have to be replaced by The National Map and related tools permitting a wide range of faster, cheaper, more sophisticated geographic analysis.
The USGS is excited about its new US Topo map series, and if you are a topographic map user, you should be too. Digital US Topo maps perform like traditional 7.5-minute quadrangle paper topographic maps while offering important technical advantages, including data layers that permit onscreen geographic analysis. You’ll like the price, too. This new generation of topo maps, “an evolutionary step toward complete digital topographic map content,” is available free of charge on the Web.
As the USGS has proudly announced:
Each map quadrangle is constructed in GeoPDF® format from key layers of geographic data – orthoimagery, roads, geographic names, contours and hydrographic features - found in The National Map, which is a nationwide collection of integrated data from local, State, Federal, and other sources.
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; and 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.
This is actually a second-generation, new and improved tool:
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.
As the US Topo product evolves, the USGS will provide digital versions of earlier edition topographic quadrangle maps and will incorporate additional geographic data layers from The National Map
Having nationally consistent data quality assured to high standards is a tremendous benefit of this approach, but there are lots of other advantages. The maps can be printed to scale or used onscreen, and there are direct "mash-up" capabilities with Google Maps®. Depending on their needs, users can select from various reference systems, including LatLong and Universal Transverse Mercator (UTM).
For further information about downloading and using US Topo, currently available coverage, and the timetable for production of US Topo maps, visit this site.
This great leap forward in map technology doesn’t mean that the legions of hikers, bikers, 4WDers, birders, climbers, and other recreationists who routinely use topographic maps are going to summarily toss their “tope sheets” into the recycling bin and start packing laptops instead. Lots of traditionalists feel navigationally challenged if they don’t have paper maps to use, and many appreciate the look and feel of the things too much to easily part with them. They don’t need batteries, either.
But I have seen the future, folks, and the paper map is a fast-fading part of it.
Picture this scene. Grizzled Outdoorsman stands next to a trail studying a topo map spread out on a boulder and anchored with pebbles. G.O. loves that map, tattered and stained though it is. Hearing the sound of approaching feet, G.O. looks up to see a 15 year-old kid. The kid says “hi,” then reaches for his belt and unclips a handheld electronic device. It contains, among other things, a complete copy of The National Map and enough GIS software to bring tears to the eyes of a professional geographer. The kid’s been brought up right, so he adopts what he hopes is a non-patronizing posture as he asks the old man: “Excuse me, sir, but what would you like to know?”
Postscript: As a basic component of The National Map, US Topo plays a vital role in the USGS National Geospatial Program, the umbrella program for USGS geospatial coordination, production, and service activities.