| Place Name | Grass Ranch Colony |
| Place Type | Census Designated Place |
| ZIP Code(s) | 57355 |
| County | Brule County |
| Area Code(s) | 605 |
| Timezone | Central Standard Time (CST) |
| Population (2022) | 77 |
| Majority Ethnicity | White 100% |
| US Congressional District(s) | South Dakota At-Large |
| State House Districts | 26B |
| State Senate Districts | 26 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 100% |
| African American | 0% |
| Hispanic | 0% |
| Asian | 0% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 0% |