In this lesson we will discuss the new topographic maps from the U.S. Geological Survey, commonly referred to as US Topo.
In this lesson we will examine:
A brief history of the USGS topographic map,
introduce US Topo maps and their content,
discuss the production and future goals of US Topo,
and learn how to access these maps for viewing or printing.
The U.S. Geological Survey was entrusted with the responsibility of mapping the country
in 1879 and has been the primary civilian mapping agency of the United States ever since.
The USGS has been generating topographic maps in a number of scales corresponding
to different regional and national grids beginning in the 1880s.
Probably the best known of these is the 1:24,000-scale map based on a 7.5-minute quadrangle.
This map series was completed in 1991 and was sporadically updated through 2006.
The 1995 Dallas, Texas map seen here is a modern example of the popular 1:24,000-scale map series.
USGS topographic maps can be categorized into two primary products.
The first is the set of maps released between 1884 and 2006.
These older, more traditionally-created topographic maps are referred to as historical topographic maps.
The release of US Topo,
the newest USGS topographic map series,
marked the end of that era and the beginning of another for USGS topographic map products.
US Topo maps are digitally mass-produced using geographic information system, or GIS, databases.
These databases stem from the national, state, and local partnerships
established as a part of The National Map, which you learned about in Lesson 2.
How to access both products will be covered later in the lesson.
First, we will focus on the historical topographic maps.
The USGS has overseen an effort to preserve these maps and make them available for online download.
This is known as the Historical Topographic Map Collection or HTMC.
HTMC is the group of all USGS topographic maps created before US Topo.
The goal has been to include every historical USGS topographic map since the first series,
which began publishing in 1884, and over 181,000 have been scanned so far.
Every scale, with a priority on the traditional 1:24,000 scale maps,
and edition, is being scanned at a high resolution and made available for download.
Seen here is a USGS topographic map of Dallas, Texas published in 1893.
It is an example of one of the earliest USGS topographic maps and is available to the public through HTMC.
In 2010, the USGS launched a completely digital replacement topographic map after extensive preparation and testing.
The new map, which will offer national coverage of all states and territories, is called US Topo.
The purpose of the US Topo map series is to serve as a nationwide topographic basemap built on current,
authoritative digital data available as a part of The National Map.
US Topo maps contain many core features of historical USGS topographic maps,
but make use of modern standards and technologies.
This 2019 map is an example of the latest iteration of US Topo for the Dallas, Texas area.
One of the easiest ways to distinguish a US Topo map from previous series is the US Topo logo at the top center of the map.
As you can see, several types of transportation are included as well as green-tinted woodland vegetation land cover,
a familiar component on earlier maps, and hydrography, or surface water features such as ponds and streams.
A closer look reveals contour lines and geographic names.
The gray layer now visible, is a shaded relief DEM, or digital elevation model.
State, county, and national boundaries are also shown in addition to limited structure types.
The footer of a US Topo map has a layout similar to previous series,
with brief metadata on the bottom left, multiple scale bars in the center, and the map name and date on the bottom right.
New to this series is a recent aerial color orthoimage.
Although US Topo is a new all-digital topographic map product,
the US Topo maps retain many of the characteristics of the traditional USGS topographic maps.
In addition to the similar detailing in the outside margins of the map,
it uses the 7.5-minute grid of the earlier map series and has a scale of 1:24,000.
As mentioned before, the digital nature of the product and the layering available in geospatial PDF format allows
a recent aerial photograph background image to be included.
Another advantage of the US Topo map series is that they are nationally consistent
and complete for the contiguous United States, Hawaii, Puerto Rico, & the US Virgin Islands.
Alaska is very close to completion as well.
Furthermore, US Topo maps can be viewed and allow for basic GIS functionality using free software.
US Topo maps will also receive updates and content expansions as more data become available.
New geographic data layers have been added periodically since the production of the first US Topo maps in 2009.
In order for data layers to be added to US Topo,
they must be available nationwide,
provide topo-related content,
and are able to be added in a practicable manner.
Layers are first added to The National Map,
the dataset upon which US Topo is based,
and are then incorporated during the next production cycle of US Topo maps.
The map layers in US Topo come from a number of sources as can be seen here.
Much of the data originate from within the USGS or through agreements made as a part of The National Map:
For a deep dive into each layer of The National Map, please see lesson 2 of this series.
US Topo maps can be easily viewed and printed from a normal office computer without specialized software or expertise.
They can be downloaded for free online in a variety of georeferenced formats.
The datum on all US Topo maps is North American 1983/World Geodetic System 1984
and latitude and longitude values are provided in decimal degrees, precise to four decimal places.
Each US Topo map has an attached metadata XML file that describes data sources and production processes,
complying with Federal Geographic Data Committee content standards for digital geospatial data.
Starting in 2009 and continuing beyond 2019, US Topo maps have been produced on a 3-year cycle.
This graphic shows a snapshot of a 2019 cycle where the oldest current US Topo maps
of the contiguous United States, produced in 2016, have been partially replaced by newly created 2019 maps.
However, as the map-refresh process takes place throughout an entire year,
please refer to the USTopoAvailability web service found at
viewer.nationalmap.gov/services
if you want to know exactly which regions have been completed at a given time.
This is the most reliable source of determining the US Topo map date for a particular area of the United States
other than downloading the maps themselves.
Content additions and updates to US Topo will persist for the foreseeable future.
For example, trails, which were first appeared on US Topo maps in 2014,
will continue to expand as additional data sources become available.
Structures will also receive continuous expansions as data is added
via The National Map Corps crowdsourcing initiative.
US Topo coverage of Alaska will also be completed by the end of 2020.
Finally, research continues into enhancements of US Topo products,
such as improvements in text placement and providing maps in alternative formats, scales,
or with customized content and areas of interest.
There are multiple ways to access the Historical Topographic Map Collection and US Topo products.
The first method is to go to the National Map Viewer at
viewer.nationalmap.gov/advanced-viewer/ and click ‘Data Download’.
This will take you to The National Map Data Download client.
Use the map interface to navigate to your area of interest,
check the boxes for US Topo or Historical Topographic Maps and click the ‘Find Products’ button.
US Topo data is also viewable in the USGS Topo Base Map.
Returning to The National Map Viewer, click ‘Services’ to view all available services and links.
The US Topo Availability service, mentioned earlier, can also be found here.
Another important thing to note is that most of the vector and raster layers seen on US Topo maps
can be downloaded or connected to individually using The National Map data download client,
The National Map services, and other online resources.
Several of the lessons in this National Map collection provide details on downloading and connecting to this GIS content.
The Historical Topographic Map Collection and US Topo maps can also be accessed through the USGS Store,
the TopoView web application, and through mobile devices.
Please see their respective training videos for a more in-depth tutorial.
In order to access and view US Topo maps, a recent operating system is recommended, as is broadband Internet access.
Adobe Reader® software, or an internet browser extension capable of opening PDFs, is needed to view PDF files.
Files are also compatible with Adobe Acrobat ®.
TerraGo Technologies Toolbar is not required, but it does provide enhanced functions for GeoPDF maps published before July of 2017.
For geospatial PDFs published since that date, Adobe’s measure tool offers similar functionality.
Please see Lesson 8a for an in-depth tutorial.
For more information, please visit the links provided here to The National Map Viewer, the Historical Topographic Map Collection fact sheet,
the US Topo fact sheet, and the US Topo Website & US Topo Map Users Guide.
In this lesson, you learned about the history of USGS topographic maps,
the Historical Topographic Map Collection,
the new US Topo maps and their content,
and finally, where to find the maps and how to view them.
Thank you for your time and attention.