HAMILTON, Mont. —

“It’s a pretty sweet spot to be in,” said economist Ray Rasker, of Headwaters Economics in Bozeman, Mont. “You can have the same job you’d have in Seattle and go fly-fishing in the afternoon. . . . It’s the quality of life. It attracts talent. Pretty soon, talent builds on itself, and word gets out.”

As small towns elsewhere saw prosperity pass them by in favor of the big cities, something unusual happened to this rural hamlet tucked in the Bitterroot Valley: It flourished.

Two local boys came home from college and launched a microbrewery that takes in more than $1 million in annual sales. Retirees arrived in droves, drawn by affordable land and recreation opportunities in the area’s snow-frosted mountains and trout-filled streams. And the federal government’s Rocky Mountain Laboratories opened a state-of-the-art biosafety facility to investigate the deadliest viral diseases, including Ebola.