How many Mormons live in Boise?

The Church of Jesus Christ of Latter-day Saints (commonly called the "Mormon" Church) does not release membership statistics for any area smaller than a state. Reporters and other members of the newsmedia may be able to find the approximate membership numbers for a city by contacting local church leaders or the Church's newsroom in Salt Lake City.
The Church of Jesus Christ of Latter-day Saints (the "Mormon" church") does not release membership statistics by city, only by state. If you need to know how many Mormons live in Boise specifically, you will need to talk to local church leadership, who have access to congregation membership records.

As of January 2012, there were 417,000 baptized Mormons living in Idaho.