One pioneer called it "the mile machine." Another, the "roadometer." Appleton Harmon made it and attached it to Heber C. Kimball's wagon on this May 12, 1847.

Now, the pioneers would know exactly how far they traveled each day. This model at the Mormon Trail Center near Omaha shows how it worked. Where the pioneers first used it is now a city, North Platte, Nebraska, and here on the grounds of the local historical society is a marker that tells about the "distance measuring device."

This day it measured the miles along the North Fork of the Platte, through an area where Indian hunters had recently slaughtered hundreds of buffalo.