1938 aerial image showing old Cannon Ball, North Dakota and the confluence of the Cannonball River with the Missouri. Courtesy Sitting Bull College Library via USDA)
In 1938, a government sponsored program took photographs of Standing Rock, capturing a moment in time before the Oahe Dam would flood the rich, tree covered bottom-lands that had provided food and shelter for people in the region for centuries. This imagery can be accessed and downloaded for Sioux county (the ND side of Standing Rock) from a useful online tool called the North Dakota Aerial Photography Dissemination Mapservice.
Sitting Bull College Library has a select collection of high resolution files mostly from along the Missouri, Cannonball and Grand rivers in areas that were inundated by the rising waters of the reservoir. They provide a unique window into the past, allowing viewers to zoom in on homes, roads and a life now covered over by the turbid waters of Lake Oahe.