Post Offices List in Douglas County, Washington:
| Bridgeport Post Office | 1011 Columbia Ave, Bridgeport, WA 98813 |
| Coulee Dam Post Office | 402 Mead Way, Coulee Dam, WA 99116 |
| Mansfield Post Office | 38 Main St, Mansfield, WA 98830 |
| Orondo Post Office | 14003 State Route 2, Orondo, WA 98843 |
| Rock Island Post Office | 224 Rock Island Dr, Rock Island, WA 98850 |
| Waterville Post Office | 113 E Locust St, Waterville, WA 98858 |