1. Holladay
2. Provo
3. Clearfield
4. Riverton
5. Roy
6. Springville
7. Lehi
8. Clinton
9. Spanish Fork
10. South Salt Lake
Utah is growing fast: the state’s population has doubled in the past 30 years, and planners expect the state will add another 2.5 million people by 2050. The fastest-growing areas are concentrated in the 90-mile stretch along Interstate 15 from Ogden to Provo, where new residents and businesses are arriving at some of the fastest rates in the country.