text: The United States Census Bureau estimates that the population of Montana was 1,032,949 on July 1, 2015, a 4.40% increase since the 2010 United States Census. The 2010 census put Montana's population at 989,415 which is an increase of 43,534 people, or 4.40 percent, since 2010. During the first decade of the new century, growth was mainly concentrated in Montana's seven largest counties, with the highest percentage growth in Gallatin County, which saw a 32 percent increase in its population from 2000-2010. The city seeing the largest percentage growth was Kalispell with 40.1 percent, and the city with the largest increase in actual residents was Billings with an increase in population of 14,323 from 2000-2010.