(James Edmondson / Flickr)

For years now, Treasure Valley cities have been among some of the fastest-growing urban areas in the country. And Idaho's not alone; since the late 1700s, there have been identifiable growth spurts in America's population that have sometimes lasted for decades.

However, have you ever wondered why population shifts like this suddenly take place?

That's a question that Tom Baerwald will be answering in his upcoming lecture with the Osher Lifelong Learning Institute. He’s been studying how and why America's metropolitan regions have changed over time, and he's joined Idaho Matters for a preview.