Title: [Lewis and Clark Expedition 200th anniversary mosaic] /
Authors: Rumsey, David, 1944-; Telemorphic, Inc.; David Rumsey Collection.; Cartography Associates.
Publisher: Cartography Associates],
Year: 2002
Subjects: Northwestern States Maps.
Abstract: 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 maps 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 1870s. These were merged with a map from the 1970 USGS National Atlas. All 3 were then placed within a mosaic of Landsat satellite imagery from NASA. Moving outwards from the expedition's route shows how the country and technology have changed since 1806. All 4 components of the 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.