The Diversity Index is a scale of 0 to 100 that represents the likelyhood that two persons, chosen at random from the same area, belong to different race or ethnic groups. If an area's entire population belongs to one race AND one ethnic group, then the area has zero diversity. An area's diversity index increases to 100 when the population is evenly divided into two or more race/ethnic groups.
| Name | County | Diversity Index | |
|---|---|---|---|
| 1. | Hinsdale Census Designated Place | Valley | 6.5 |
| 2. | Boneau Census Designated Place | Chouteau | 8.7 |
| 3. | Town of Denton | Fergus | 9.2 |
| 4. | Harrison Census Designated Place | Madison | 10.2 |
| 5. | Conner Census Designated Place | Ravalli | 10.5 |
| 6. | Montaqua Census Designated Place | Carbon | 10.8 |
| 7. | Town of Plevna | Fallon | 11.1 |
| 8. | Joplin Census Designated Place | Liberty | 11.7 |
| 9. | Azure Census Designated Place | Hill | 12.0 |
| 10. | Lodge Pole Census Designated Place | Blaine | 12.2 |
| 11. | Town of Hingham | Hill | 12.3 |
| 12. | Town of Grass Range | Fergus | 12.3 |
| 13. | Beaver Creek Census Designated Place | Hill | 12.4 |
| 14. | Town of Lodge Grass | Big Horn | 12.7 |
| 15. | Rudyard Census Designated Place | Hill | 12.9 |
| 16. | Belfry Census Designated Place | Carbon | 13.3 |
| 17. | Town of Clyde Park | Park | 13.4 |
| 18. | Fallon Census Designated Place | Prairie | 13.4 |
| 19. | Town of Ekalaka | Carter | 13.6 |
| 20. | Heart Butte Census Designated Place | Pondera | 13.7 |