I just stumbled across a nifty little tool created by, of all people, dear ol’ Uncle Sam. The USGS is providing free downloads of topo maps over at http://store.usgs.gov . Just click the “Map Locator” link on the left side. The interface is a little weird, but it provides access to PDF versions of maps like the 7.5-minute Mt. Bachelor quadrangle (snapshot at right). I’m not sure how long this service has been available – I just found out about it over at SierraDescents.com.
USGS topo maps have been the gold standard in terrain-based map information for decades, so it’s neat to see them offered for free. The fact our government is using Google Maps to create a zoomable, pannable, online topo map is also cool. It’s a pleasant change from the usual, half-baked solutions that .gov sites normally offer.
It also invites the inevitable comparison to Google’s own “terrain” view which, at first glance, is hella better looking. The comparison is particularly interesting because I’m pretty sure Google’s view was generated from the USGS topo data. (there are some suspicious oddities about Google’s view right about where the USGS topo maps intersect). The basic elevation contours are the same and the views have the same roads and fireroads. But only the USGS maps show trails, buildings, mines, or other landmarks that make these types of maps so fun and useful.
Unfortunately the topo map I’m looking at (the Mt. Bachelor quad) hasn’t been updated in 27 years, so trusting it to be accurate in any of these details would be foolish. Google could have probably included this information on it’s terrain view but likely decided to avoid the legal liability issues involved in having incorrect, out-of-date landmarks on it’s mapping service. The USGS topo maps have clear statements about how and when the map was last updated on each quadrangle, something Google lacks.
This dated-ness has long been a complaint of topo maps or, if not a complaint, at least an accepted weakness. It leads one to speculate about whether there is a better way to keep topo data current, a way for our government to, say, crowdsource out the work of doing field surveys. Imagine an iPhone app that allowed you to tag your current location with an icon and a comment and submit that to a [government?] database of topo data. This would allow local organizations like COTA and CONC to maintain the locations of new ski shelters and mountain bike trails in near real-time, rather than waiting 20 years for the next USGS update.
In fact, if the USGS focused on managing raw map data and providing an open API to that data, and left the actual rendering of maps to companies like Google, it might make for an interesting paradigm shift in the world of cartography.
[Hmm... one could argue this has already started to happen as small groups turn to Google's Maps API to create custom maps for things like specific types of geodata: trails, geocaches, radio tower locations, etc.]