Lewis and Clark Commemoration Mosaic

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In recognition of the 200th anniversary of the Lewis and Clark expedition, David Rumsey and Telemorphic, Inc. created this mosaic of expanding geographic knowledge and development of the American west.

Using historical map content from the David Rumsey Collection, the central portion of the 1814 Samuel Lewis map of Clark's original drawing was merged with and surrounded by the General Land Office's first complete land survey, completed in the late 1870's. These were then merged with a map from the 1970 USGS National Atlas. All three were then placed within a mosaic of Landsat satellite imagery from NASA.

Moving outwards from the expedition's route shows not only how the country has changed since 1806, but how technology has changed as well. All four components of this mosaic have been georectified so as to geographically match one another. Using a GIS, numerous identifiable landmarks were located on the maps and matched to a common coordinate system. Using these locations as control points, the entire map is then warped and stretched to conform to this coordinate system.