Is there some central place to find current business plan competitions?
Enter the Project Grow Challenge presented by Entrepreneur and Canon USA for a chance to win up to $25,000 in funding for your business. Deadline is Sept. 15 2015. Click here to enter.
No, there isn't really a central site. The closest one I know of is this: http://www.paloalto.com/academic/competitions/. But there are competitions coming up all the time. Search Google and Yahoo, and check with all the local universities by calling up their entrepreneurship centers in their business schools. You mention Idaho--Boise State has an active entrepreneurship center and sends teams to compete in a lot of the competitions I'm involved with (I'm a frequent judge).