The Tri-State Gas Engine & Tractor Show is held annually in Portland, Indiana. It’s billed as the World’s largest. If it is or not may depend on how you defined it. In regards to gas engines I have little doubt that it is. It was going to be a hot day so I got there at 8:00 AM, by 11:00 AM I had enough.
But the main thing that distinguishes this show from others is the number of gas engines displayed such as this 1923, 50 hp, Fairbanks-Morse.
I believe the total number of full size farm tractors at the show was supposed to be between 700-900. There were several I had not seen before such as this Brockway.