- Department of Transportation. Federal Highway Administration. Office of Planning, Environment, and Realty. Office of Natural and Human Environment. National Scenic Byways Program. 1991-9999
- National Archives at College Park - Still Pictures
The original finding aid described this photograph as: Original Caption: Two motorcyclists lean into one of the many twists and turns along the mountain roads of the Peter Norbeck Scenic Byway. Location: South Dakota (43.883° N 103.585° W) Status: Public domain. Photo by Stephen Keegan.