Ismay began as a Milwaukee Railroad Station on O'Fallon Creek. The town originated with the building of the Milwaukee Railroad in 1907. The first school was established at that time by Edwin Stanton.
In May of 1993, the town of Ismay was contacted by a radio station in Kansas City, Missouri. The station had a special request for the town to consider changing the name of the town to Joe, Montana for the duration of the football season.
The radio station promoter felt that this was a great way to honor their newly signed Kansas City Chiefs quarterback, Joe Montana, the man.
Ismay, population 22, agreed. On July 3, 1993, it was official. Ismay was Joe. In celebration, the town organized a ranch rodeo, a parade, and a night show for July 3. The events drew over 2,000 spectators. They hoped to raise a couple thousand dollars to cover the annual operating cost of their volunteer fire department. The mayor, who earns $4 a month for his mayoral duties, proudly reported that by February of 1994, the town had netted nearly $70,000.
Ismay is located southeastern Montana, northwest of Baker.