| Place Name | Mad River |
| Place Type | Census Designated Place |
| ZIP Code(s) | 95552 |
| County | Trinity County |
| Area Code(s) | 707 |
| Timezone | Pacific Daylight Time (PDT) |
| Population (2022) | 301 |
| Population Growth Rate (2010-19) | -14.05% |
| Majority Ethnicity | White 88.33% |
| US Congressional District(s) | California 2nd |
| State Assembly Districts | 2 |
| State Senate Districts | 2 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 88.33% |
| African American | 0% |
| Hispanic | 3% |
| Asian | 0% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 8.67% |