An interesting data visualization from The New York Times shows the majority of the people living in Montana were born there.
The Times created this chart (and one for each state) showing state-to-state migration going back to 1900. At the turn of the 20th century, many of the people living in Montana were born outside of the United States, that’s not a big surprise given the westward migration of some foreigners who headed to Big Sky Country in search of striking it rich on gold, copper, and other natural resources.
By 1950, the majority of the people living in Montana were born there. The share of native-born Montanans peaked in 1970 at 61 percent. By 2012, 54 percent of the people living in Montana could call themselves native. By contrast, less than half the population of Idaho are natives.
Like other western states, the bulk of the people moving in to Montana are from California, Washington, and Oregon.
My paternal great-grandparents moved to Montana sometime before 1913. It’s not clear when my maternal great-grandparents arrived in Montana from Ireland, family history shows it was sometime around 1920.