This puzzler was inspired by a non-railfan friend, who brought me a picture of his grandfather posed in cab window of a steam locomotive. He didn't know much about the locomotive, and wanted to know more about it. When I saw the initials of the railroad on the locomotive, I saw a Frisco connection. In 1927 the Frisco cancelled a trackage rights agreement with another railroad which ran nearly 80 miles over the Frisco rails. I don't believe that any other railroad had this many miles of trackage rights ON Frisco rails. What railroad was it, and why did the Frisco nix the agreement?