Midvale has a multitude of theater opportunities. 

Tickets are required for Theater Production events.
Tickets: $5/general admission, $3/chlidren(3-12)&seniors(60+), $20family pass(one household)
Group rates: $3/person for groups of more than 10

Upcoming Theater Productions:

Missoula Children's Theater: Treasure Island
Basically, this is a theater-camp-in-a-week.  And a great experience to boot. 
Monday, September 13, 2010 through Friday, September 18, 2010
For more info, see the Missoula Children's Theater: Treasure Island tab on the top menu.