the book of mormon tour in june

In June the tour is playing in peoria, IL. and then later on in the month it is playing in Chicago IL. with one city as a buffer. My question is why would they even tour to Peoria? I get its a totally separate city, but why not make it easier for the cast and just go to one of the cities or why wouldn't they just stay in the same state and not have that buffer city.

There are a bunch of factors that play into the routing of a tour. They could have been booked in the cities weeks or even months apart so the two other cities filled in between, or Peoria or Chicago could have had a space conflict, etc.