The sign would have been stolen sometime at night, during the week leading up to the Iowa game in 1935. The week was already filled with so much hype that few would have noticed the missing butcher shop sign. Iowa's anger over the 1934 Gopher - Hawkeyes game (48-12) had carried through to build up to the 1935 tilt. Governors from both states weighed into the pre-game trash talking.
If you haven't heard this part of the story before I'll quickly fill you in. Iowa Governor, Clyde Herring, still upset with how Hawkeyes RB Ozzie Simmons had been knocked out in the 1934 game said "If the officials stand for any rough tactics like Minnesota used last year, I'm sure the crowd won't.