US Topo - 33 of 32
US Topo FAQs - 32 Found
Why are there no trails, powerlines, libraries, PLSS lines, etc. on US Topo maps?
The original USGS 7.5-minute topographic map series (1945-1992) included feature classes that are not yet shown on US Topo maps. Examples include recreational trails, pipelines, power lines, survey markers, many types of boundaries, and many types of buildings. The USGS no longer does field verification or other primary data collection for these feature classes, and there are no national data sources suitable for general-purpose, 1:24,000-scale maps. For many of these feature classes, USGS is working with other agencies to develop data. Over time, as these data become available and are included in The National Map, that content will be added to the US Topos.
Because US Topo maps are mass produced from GIS databases, some features shown on traditional maps may never be included on US Topo. For example, it is doubtful a national database of isolated ranch windmills and water tanks will ever be built.
The most-requested additional feature class is recreational trails. Trails are problematic due to a lack of national data sources, but the major federal land management agencies and other organizations are beginning to make data available. US Topo maps began including the National Scenic Trails in 2013. The U.S. Fish and Wildlife Service (FWS) provided trails for their lands in 2013. The U.S. Forest Service (USFS) provided data for Colorado in 2013, and in 2015 began publishing trails for National Forests in other states. In October 2014 we began showing trails contributed by the International Mountain Biking Association (IMBA), a non-government volunteer organization. Discussions are in progress with the Bureau of Land Management (BLM) and the National Park Service (NPS). We expect the number of recreational trails on the maps to steadily increase in the coming years.
Other feature classes that are the subjects of frequent questions:
- PLSS -- Absence of Public Land Survey System (PLSS) information was a major problem during the first 3-year production cycle (2010-12), but in the second cycle (2013-15) was largely solved. As of October 2015, PLSS has been published on US Topo maps in 19 states. At least five more states will be added to this list in 2016. PLSS is also included on Alaska maps. The Bureau of Land Management (BLM) provides these data, often in cooperation with state agencies. The PLSS layer is turned off by default when a map is opened in Acrobat Reader, and must be clicked on by the user; the reason is that displaying the PLSS network and the U.S. National Grid together leads to confusing visual clutter.
- Railroads -- The oldest US Topo maps do not show any railroads. In 2012 we began publishing railroad data provided by the Federal Railroad Administration (FRA). This dataset, though positionally accurate, was known to be less than 50% complete. In 2014 we changed data sources, to a dataset provided by a Department of Defense contractor. This dataset is believed to be at least 95% complete for active mainline track, and is expected to continue to improve.
- Boundaries -- see this FAQ.
- Buildings and structures -- Traditional topographic maps locate and label a variety of public buildings and other structures, such as courthouses, libraries, visitor centers, transportation terminals, stadiums, towers, and bridges. National public domain datasets of these feature classes do not currently exist. Although these kinds of features are not generally within USGS scope, we are developing a long-term strategy for maintaining selected structures data. These efforts depend on cooperation with other government agencies, and also a new project of Volunteered Geographic Information (VGI). US Topo maps currently show 10 structure feature types. We hope to add more in the coming years.
- Mountain peak elevation labels -- see this FAQ.
- Powerlines, oil and gas pipelines, other energy infrastructure -- Except for a few unusual instances, such as the Trans-Alaska Pipeline, these features are not shown on US Topo. National public domain datasets do not exist, and even if they did, adapting them to general-purpose maps would be difficult. In some cases there are also security reasons for not publishing these data.
- Landmarks -- Unique landmark features are a surprisingly difficult problem. Such features may include buildings, natural features, isolated monuments, points of interest, and transportation features. No national GIS database of landmark features exists, and constructing one is problematic. Nevertheless, not having such a dataset leads to cartographic oddities, such as not labeling the White House. The US Topo project hopes to eventually address this problem as part of the buildings and structures issue discussed above.
- Remote roads -- Traditional topographic maps were compiled in part from direct field observation, and were therefore a unique source of information for remote and unimproved roads. From mid 2010 to late 2015 US Topo maps used commercially licensed road data. Commercial data are accurate and complete in populated areas and along transportation corridors, but less so in remote and unpopulated areas. Building a national public domain road dataset that can rival the traditional topographic map series for overall completeness and accuracy is a long-term problem, but is being discussed by USGS, USFS, Census Bureau, and U.S. Department of Transportation (DOT). In October 2015, the US Topo project and the other products of The National Map switched data sources from commercial data to public domain road data from the Census Bureau. US Topo maps have always used public domain data from USFS on National Forest lands.
- Recreational features (campgrounds, boat docks, swimming pools, golf courses, etc) -- These are basically the same problem as either recreational trails or structures, discussed above, and some may eventually be addressed in the same ways. However, there are many of these feature types, and most will never be high priorities for USGS mapping.