David Rumsey Map Collection

Georeferencer Added to Online Library

Help Us Find Locations for Our Maps

Georeferencer is a new application we have added to our online library. It allows you to overlay historic maps on modern maps and other historic maps. The overlaid maps reveal changes over time and enable many kinds of analysis and discovery. Read more about it on our Georeferencer page. The image below from Georeferencer shows San Francisco Mission Bay in 1857 on the left compared with the modern map of San Francisco on the right, showing Mission Bay completely filled in. The two maps are perfectly aligned in Georeferencer in the Side-by side view and the red dot shows the same location in both maps. You can pan and zoom the two maps in sync.

Here the map in the 2D view in Georeferencer is overlaid on the modern map and the transparency slider used to show dramatic changes in the shoreline and the filling in of Mission Bay over the ensuing 100 years.

You can choose your own maps to georeference by Searching LUNA or help us georeference the entire online map library by using our Random Map link which will open maps that are part of our First Pilot Project. The video below gives a quick explanation of the process. Users who georeference the most maps will be recognized on our site. The First Pilot Project will include over 10,000  maps of major cities and regions throughout the world. Recently Georeferenced maps can be viewed by image or by location.

Klokan Technologies developed Georeferencer with the Moravian Library. You can combine and compare maps found at the Georeferencer pages at the National Library of Scotland and the British Library with maps from our collection in Georeferencer, just use your Login at those two online libraries Georeferencer pages and make Favorites of maps found there. Those maps will then show up in your Favorites list here and at those libraries as well.