Washington State’s Department of Natural Resources collects and publishes LiDAR data covering much of the state. LiDAR imagery is created by flying specially-equipped aircraft over areas of interest and using light pulses to determine the precise distance to the ground. This data is later assembled into elevation maps. You can browse the maps using the DNR LiDAR Portal interactive viewer.
The LiDAR maps are very high resolution (about 2 meters per pixel). In addition, LiDAR penetrates tree cover to reveal the shape of the ground hidden underneath. These attributes make LiDAR data a great resource for mapping streams, hiking trails, and forest roads.
Above: Clark Mountain area, showing glaciers and streams
Below: Paradise in Mount Rainier National Park, showing roads, parking lot and hiking trails.
All of the DNR LiDAR maps are in the public domain, so it be used without worry when contributing to OSM. About one-third of the state has already been surveyed, and the DNR plans to survey the entire state.
Using DNR LiDAR maps in iD is very simple. The DNR runs an ArcGIS server which provides a WMS endpoint. iD can use this endpoint to display a custom imagery layer.
Launch iD (osm.org/edit). Open the Background Settings panel on the right (shortcut: B), choose “Custom” from the Backgrounds list, and then paste this text into the box in the pop-up that appears:
That template string tells iD how to query the DNR’s WMS server. Click “OK” and you should see the imagery appear right away.
Special thanks to the following people: