This layer is a georeferenced image of a map of the track of Lewis and Clark in the western United States, created in 1804. The original map appears in 'History Of The Expedition Under The Command Of Captains Lewis And Clark, To The Sources Of The Missouri, Thence Across The Rocky Mountains And Down The River Columbia To The Pacific Ocean. Performed During The Years 1804-5-6. By order of the Government Of The United States. Prepared For The Press By Paul Allen, Esquire. In Two Volumes. Vol. I. Philadelphia: Published By Bradford And Inskeep, New York. J. Maxwell, Printer. 1814 ... Vol. II.'The historic map layers in the Google Earth Rumsey Map Collection have been selected by David Rumsey from his large collection of historical maps, as well as some from other collections with which he collaborates. All the maps contain rich information about the past and represent a sampling of time periods, scales, and cartographic art, resulting in visual history stories that only old maps can tell. Each map has been georeferenced by Rumsey, thus creating unique digital map images that allow the old maps to appear in their correct places on the modern globe. Some of the maps fit perfectly in their modern spaces, while othersgenerally earlier period mapsreveal interesting geographical misconceptions of their time. Cultural features on the maps can be compared to the modern satellite views using the slider bars to adjust transparency. The result is an exploration of time as well as space, a marriage of historic cartographic masterpieces with innovative contemporary software tools.