| Locality | Post Code |
|---|---|
| Arbuckle, Colusa | 95912 |
| Codora, Colusa | 95970 |
| College City, Colusa | 95912 |
| Colusa, Colusa | 95932 |
| Fouts Springs, Colusa | 95979 |
| Grimes, Colusa | 95950 |
| Leesville, Colusa | 95987 |
| Lodoga, Colusa | 95979 |
| Maxwell, Colusa | 95955 |
| Princeton, Colusa | 95970 |
| Sites, Colusa | 95979 |
| Stonyford, Colusa | 95979 |
| Wilbur Springs, Colusa | 95987 |
| Williams, Colusa | 95987 |