You're in a pretty bad section of the country when it comes to speedcubing. My friend, Spencer, hosted Idaho Open 2014 not too long ago, and it had 27 people who pre-registered. There probably would have been more if the comp hadn't happened on December 27th, between Christmas and New Year's where flights were expensive and roads are icy :/
Yeah I have noticed that there aren't many people in my area even in Boise. Any suggestions to maybe find something somewhere else or suffering along the same line?