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TopOSM showing the hills east of Oakland and Berkeley, CA.
TopOSM showing the hills east of Oakland and Berkeley, CA.
Slippy map:
Style website: Ahlzen/TopOSM

TopOSM is an OpenStreetMap-based topographic map, similar in style to the USGS and National Geographic topographic maps and (to some degree) Google Maps in "Terrain" mode.

Note: map coverage is currently limited to the USA only.

The map features both contour lines and relief shading derived from data sources such as the USGS National Elevation Dataset, MassGIS and SRTM. Hydrographic features, such as lakes, rivers and wetlands, come from the USGS National Hydrographic Dataset and MassGIS. Roads, place names and all other map features are from the OpenStreetMap project.

NOTE: TopOSM maps are not updated as frequently as many other OSM based maps. Therefore, the map may not represent the latest data from the OpenStreetMap database. If you make a change in OpenStreetMap, it may take a significant period of time before it appears on


TopOSM coverage is currently limited to the USA. Worldwide coverage is a long-term goal.


The primary goal of TopOSM is to create a high-quality, detailed, highly readable and aesthetically pleasing topographic map. Below are examples of some of the features of TopOSM maps.

Hillshading and contour lines

Hillshading and contour lines are derived from the 1/3 arc-second National Elevation Dataset from USGS. The hillshading layer is color-coded with a typical green/brown/white gradient by elevation. Additionally, on higher zoom levels, contour lines are available with 50 ft intervals with a major contour line every 250 ft. Contour lines are marked with elevation labels, in feet.

The Olympic Penninsula and the Puget Sound area, Washington state, at zoom level 7. Hillshading and color by altitude.

Interstate 90 over Snoqualmie Pass, east of Seattle, at zoom level 11. Contour lines with a 250 ft interval are visible.

Snoqualmie Pass at zoom level 13, with 50 ft contour lines.

On recent TopOSM maps, the hillshading and contour line layers can be individually shown or hidden to customize the map.

Yosemite valley with contour lines hidden.

Yosemite valley with contour lines but no hillshading.


The National Hydrographic Dataset from USGS provides very detailed hydrographic information, including rivers, perennial and intermittent streams and ditches, lakes and reservoirs, wetlands and glaciers, most of which are rendered on the map at higher zoom levels.

TopOSM near Boulder, CO, with a multitude of streams, lakes and reservoirs from the NHD visible. Intermittent streams are shown as dashed lines.

Example of lakes, streams and wetlands near the east portal of the Moffat Tunnel through the Rocky Mountains.

Map features

Some of the symbols used on the TopOSM map.

Most features on the map, such as cities, roads, buildings and railroads come from the OpenStreetMap project. As a consequence, the TopOSM map will constantly be improved and updated. Since the primary use for a topographic map are outdoors activities, special priority has been to include related features, such as hiking trails and features, bike paths, shelters, parks and nature reserves.

Hiking trails on Cougar Mountain near Issaquah, WA.

Road shields are customized for the United States, and a custom set of map symbols, inspired by the style commonly found on topographic maps, was created.

Example of interstate shields, Los Angeles, CA. Example of a US highway shield on the Redwood Highway (US 101), CA.


Similar to many printed maps, rather than having a solid outline, labels on TopOSM provide spacing between the text and other high-contrast features on the map, for easy reading without cluttering the map.

Magnified to 200%, note that road fills are visible behind labels, despite the "halo".

Map key

A (collapsible) map key is included with some TopOSM maps to aid interpretation.

TopOSM Massachusetts with the map legend visible.

Source code

All code, scripts and stylesheets, as well as (brief) instructions, required to set up your own TopOSM rendering server is on GitHub, at:

(an older version of the TopOSM code is available from the OSM SVN repository, at

Credits and licensing

TopOSM was created by User:Ahlzen, with contributions from several others, including Ian Dees, Nick Thompson and Phil Gold.

The author also wishes to thank the US Geological Survey and the State of Massachusetts for providing me with data for the project, and all OpenStreetMap contributors.

OpenStreetMap Data is available under the Open Data Commons Open Database (ODbL) license. NED and NHD data from USGS, being the work of a US goverment agency, is considered public domain. MassGIS data is free for any use, as long as proper attribution is given. Therefore, this topo map is available under the CC-BY-SA license as well.

See also