7 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Inverness | Arapahoe County | 3,447 |
| Idaho Springs | Clear Creek County | 1,650 |
| Indian Hills | Jefferson County | 1,329 |
| Ignacio | La Plata County | 845 |
| Idledale | Jefferson County | 318 |
| Iliff | Logan County | 238 |
| Idalia | Yuma County | 116 |