The data were collected from standard USGS topographic maps. Rather than measure fixed distances along the roads and guess at the elevation for each point, I chose to take distance measurements at every contour interval. For long intervals and known retrogrades, I interpolated other values as well. There are a number of sources of error in my technique: Note also that since I am measuring horizontal distances, the distance along the X-axis should be shorter than the actual distance you would travel along the road.
Mike Hibler <>