Locating and Assessing Oregon Trail Ruts in Nebraska with Aerial Stereophotographs, Satellite Imagery, and LiDAR

Abstract: The Oregon Trail was the primary westward migration route into the trans-Missouri west for Euro-Americans prior to completion of the transcontinental railroad in 1869. Remnant wagon-wheel ruts are preserved in several locations in Nebraska under various environmental conditions and land uses. These ruts exist in soils formed in unconsolidated sediments (particularly loess) and soft bedrock. Most of the ruts are in long-maintained pastures on slopes and preserved in parks, although several are preserved in relatively flat terrain, and one set is in a recently plowed field. We identify remnant ruts in historical aerial photographs dating back to the late 1930s, in satellite imagery taken from the 1980s to the present, and—for the first time—in recent LiDAR images. LiDAR proves the easiest and most consistent means for identifying ruts at all our sites. In contrast, the visibility of ruts in aerial and satellite imagery depends upon local environmental conditions and the year and season in which the imagery was collected. Our results are relevant to the identification and management of other types of cultural and natural features in working landscapes.