To understand what energy means to Wyoming, spend time in a town like Gillette, which proudly calls itself the energy capital of the nation. Communities like it have lived the full, dizzying arc of the energy economy, and their fortunes rise and fall with the industry they serve.

In boom years, an energy town is a place of frantic energy. Workers pour in to fill high-paying jobs, new subdivisions and shopping centers sprout, restaurants stay busy, and the schools fill with the children of newcomers. The money flows freely, and optimism runs high.

The busts are just as dramatic in the other direction. When coal falters or oil prices crash, layoffs sweep through, families move away, home values sag, and the businesses that thrived on energy paychecks struggle to survive. The same qualities that make a boomtown exciting make it precarious.

Residents of these communities develop a certain resilience, a hard-won understanding that good times do not last and bad times eventually pass. Many have learned to save during the booms and hunker down during the busts. As the energy industry transforms, Wyoming's boomtowns face perhaps their greatest test yet, and how they adapt will say much about whether the state can build a future beyond the cycle of boom and bust.