Rocky discovered early on in his life that he could just hop on freight trains to migrate throughout the mountainous northern regions of the US. Thus he learned professional hobo skills like dodging railroad police ("the bulls") and learning schedules to make connections. After several beatings by the bulls and finally tiring of cold mountain winters, Rocky started hanging around the station near Glacier National Park. He helped out where he could, typing train orders and bills, operating the signal system and using the telegraph to communicate with other stations. This was all done using his nose, normal procedure for US railroads. He eventually became a station agent through his diligent work ethic and because nobody else wanted to work in the winter cold.
However, one winter day during a snowstorm, he was hanging a mailbag on its crane for pickup and got tangled up with it. As a freight train passed, the arm holding the bag swung out and slapped Rocky against the side of a boxcar, where he was stuck, frozen. Meanwhile, Great Northern executives were in a hotel discussing how best to promote the railroad when the train with that boxcar passed their window. Rocky was then seen and it was decided right then and there that a mountain goat would be the logo. The only difference from what they saw would be that their new mascot would be smiling. When Rocky's train finally arrived at a yard and stopped, he was rescued and immediately fired for leaving his post without permission, joyriding on trains, getting blood on a boxcar, plus about 30 other violations.