TopoView highlights one of the USGS's most important and useful products, the topographic map. In 1879, the USGS began to map the Nation's topography at several levels of detail, in order to support various land use planning and decision-making initiatives. As the years passed, the USGS produced new map versions of each area. TopoView lets users access the many and varied older maps and is especially useful for historical purposes, as the names of some natural and cultural features have changed over time. In this detailed guide, we’ll take a tour of the various components of topoView and show you what each can do. Have a question? If you can't find an answer contact us. We're here to help.
Check out our quick start video to see topoView in action. The video is a good place to see live examples of many of the items described in the detailed help guide below.
How To Read These Maps
A topographic map shows contours on the land surface and may include many different line and point symbols, for features such as streets, buildings, streams, mines and caves, natural and political boundaries, and vegetation. To help you read these maps, the USGS provides these symbol guides:
- For the historical topographic map collection (pre-2006), please see the topographic map symbols guide
- For the digitally-produced, US Topo maps (2009 and more recent), please see the US Topo map symbols guide
In most web mapping interfaces, there are a variety of ways to zoom/pan around the map. In topoView, panning is enabled by default. Simply click anywhere on the map, hold down the left mouse button and drag the mouse. For zooming into an area, we offer the magnifier tool, but instead you may find it easier to:
- Hold the shift key and drag a box over your area of interest
- Double-click on the map (triggers a single zoom-in event)
- Use the mouse scroll wheel (also used for zooming out)
To zoom out click or the icon, which returns you to the initial map view of the conterminous United States. Users can also use the mouse scroll wheel for quickly zooming out of an area. For tablet users, a simple multi-touch pinch gesture lets you zoom in and out of the map area.
There are two related tools that let you toggle between current and previous views, and may be useful if you’ve been navigating around the map. Clicking will return you to the map view just prior to the one you’re currently looking at. If you’ve used to “step back”, then will let you “step forward.”
Zoom to location
To find maps for a location, such as your house, or town, or larger area, click on the icon. There, you can enter very specific information, such as your full street address (e.g., 12201 Sunrise Valley Dr., Reston, VA) or latitude/longitude coordinate pair (e.g., 37.25, -115.82), or more general information (e.g., zipcode, town name, or park name).
If you provide a unique and specific location, like an address or a zipcode, topoView will zoom to it and leave a marker at that location. If you enter something more general (e.g., 'Columbus'), you may see a dropdown list to select from (e.g., Columbus, OH; Columbus, GA; Columbus, IN) – select one, and you'll be zoomed to that feature. If you enter something that's very general (e.g., 'Georgia', or 'Shenandoah Mountains'), topoView will zoom you to the 'centroid' (or the center point) of that geographic feature.
TopoView allows you to see your current location by clicking on the icon. If you have geolocation services enabled on your device/browser, you will be zoomed to your current position. Note that the accuracy of the geolocation tool depends on a variety of factors including user hardware (GPS enabled) and network connection.
When you enter the topoView site, you'll see a grid of yellow boxes. These are the 1:250,000-scale (1° X 2°) topographic map series, which are the least detailed in the collection, but they cover all of the conterminous U.S. and Alaska. The 'Map Scales' selector box gives you the choice of which map scales to view. It's common to see map scales listed as representative fractions (e.g., 1:100,000). For example a 1:24,000 map means that 1 unit of measurement on a map – 1 inch, or 1 centimeter, or 1 foot – represents 24,000 of that same unit on the ground. The smaller the map scale number, the more detailed the map is, but the less area it covers. Learn more about map scales here.
The scale numbers in the map scales selector box represent common USGS map series scales. In order to provide a useful but compact Map Scale selector, we combined maps of similar scale into the bins that we show in the selector box. For example:
In the example below, we show the distribution of topographic maps of different scales around the Seattle area. As we select a map scale, the 'Map Records' counter at the bottom of the map window is updated to show the number of maps in the map window. You can also see all maps, at all scales, by clicking 'Show All'.
When a map scale is selected (with the exception of 'All Scales'), map labels will appear as you zoom in. If you would like to 'hide' the map selector box, click the icon.
Getting Map Information
When you click on any of the colored map boxes, the map information window will appear in the lower left of the screen. Along the left side of that display, you'll see the map quadrangle name and some information about the particular edition that's being shown. In the center, you'll see the list of downloadable files.
On the right, you'll see a thumbnail image (click this to preview in high-resolution) showing the most recent map of the quad that you selected or searched. Next to the preview image you'll find a count of the number of maps that were published at that particular point.
TopoView offers the topographic maps in a variety of downloadable file formats, in order to meet a range of user needs. These formats are:
- GeoTIFF – The GeoTIFF files are a compressed, TIFF image format, with embedded georeferencing information so that the map can be used directly in a Geographic Information System (GIS). GeoTIFFs downloadable through topoView are highly compressed 300 dpi TIFF images with georeferencing information embedded in the header. JPEG-in-TIFF compression with a YCbCr colorspace was used to compress both the tiled TIFF file, and the reduced resolution internal overlays. The GeoTIFFs are generated at true scale, allowing users to plot the map at the intended map scale in cases where a hard copy is needed.
- KMZ – The KMZ format is a compressed form of the KML format which is used for displaying the maps in Google Earth. Provided you have Google Earth installed on your computer, simply double-click on the KMZ, or drag it into the Google Earth interface. The KMZ file includes information about the particular map that you downloaded in both the places pane, and in the overlay map popup.
- JPEG – (Browse JPEG) The high-resolution JPEG format is useful for getting a quick view of the map in order to find place names or simply explore the map area without the need for downloading a large file. The downloadable JPEG is identical to the image you'll see in your browser when you click on the thumbnail image. But to ensure that the JPEG downloads to your computer, we enclose it in a zip file. Alternatively, simply click on the map thumbnail, and download the JPEG from your browser window.
- GeoPDF – A Portable Document Format (PDF) with geospatial extensions (GeoPDF®). GeoPDF's can be viewed and printed with Adobe Reader or comparable PDF viewing software. The geospatial extensions provide limited GIS functionality, such as displaying ground coordinates and measuring distances and areas.
Topographic mapping of the United States began in the late 1800's. The first maps were of large areas, at scales of 1:125,000 and 1:250,000 (see Map Scales section). As mapping of the country progressed, more detailed maps were made, and by the 1930's, mapping at 1:24,000 was being done systematically (the 1:24,000 scale provides highly detailed map information to the public, and has become the USGS's principal topographic map product).
The timeline slider, along the top of the window, will let you view and download maps of any time interval you choose. In addition, it's a powerful, easy-to-use tool for learning about the progression of topographic mapping across the country over time.
If you've selected a time interval (for example, to show the maps published between 1889 and 1927), then all maps that are not within that interval will be excluded from searches and from the map records table. If you want to be sure to find a map of your area, reset the timeline to the full extent.
Along the top right edge of the map information window, you'll see the icon. This tool generates a table of map records at the same point as the map shown in the map information window. The table lets you inspect/compare details about maps at a certain point, and help you decide which map(s) you want to download. When the table appears, move your mouse cursor (or tap, on a touch device), from one map record to another.
You'll see the map information change to match the newly-highlighted record. If you look at the map interface, you'll notice the map outline (red box) changes to show the location of the highlighted map.
If you know the name of the map you're looking for, you can enter it in the search tool, which is located in the upper right corner of the window. You can enter the full name, or just a partial name (for example, we entered 'shel' in the graphic below).
Once the search term is entered, the Map Information popup and Map Records table will appear. All maps that meet your search criteria will be shown. Be aware that your search will be limited to the current timeline and map scale that you've selected. To increase the odds of finding the map, reset the timeline to the entire date range, and set map scale selector to 'Show All'.
Baselayers & Opacity
TopoView is designed to help you quickly browse the 178,000+ published USGS topographic maps. To assist you in locating the maps you need, we provide baselayers in the background, underneath the colored boundaries of the topographic maps. In the upper left corner of the map window, you can choose from these two baselayers:
The opacity slider, in the upper right corner of the map window, is helpful for fading in/out the map boundary overlay colors, so that you can see the roads, towns, and topographic information on the selected baselayer. Click the icon and use the slider to adjust the overlay transparency.
Table Sorting and Filtering
Depending on your search criteria, the number of maps that are found can vary greatly, from zero to thousands of maps (maximum number of records returned is 1,000). If your search found a large number of maps, the map records table can become quite large. We recommend using the sort and filter features to browse your search results more efficiently.
The example above shows a search for maps named 'preston'. Eighteen maps were found (as seen in map counter). We sort the set of returned records by clicking on the scale column, and while holding the shift key, click on the date column. This effectively lets us sort on multiple columns. We filter the sorted set by entering 'peak' and then '1915'. Filtering looks for any combination of characters/numbers anywhere in the table record.
Sharing & Pinning
Click on the icon to open the sharing window. The sharing window lets you send your current topoView window settings to your favorite social networking sites like Twitter and Facebook. You can also copy the URL string for pasting in a text editor, or sharing via email or web browser.
Click on the icon in the map information window to pin your map. Pin descriptions are pre-built with information about the map being pinned. Descriptions can be edited if a customized description is desired. Note that the social networking capabilities in topoView require you to have an account with the particular social networking service you're interacting with.