Hanford Reach
| Hanford Reach | |
| River | |
 A section of the Hanford Reach | |
| Country | United States |
|---|---|
| State | Washington |
| Part of | the Columbia River |
| Source | Base of Priest Rapids Dam |
| - location | Near Desert Aire |
| - elevation | 443 ft (135 m) |
| - coordinates | 46°38′35″N 119°54′39″W / 46.64306°N 119.91083°W |
| Mouth | Lake Wallula |
| - location | Richland |
| - elevation | 340 ft (104 m) |
| - coordinates | 46°16′46″N 119°16′03″W / 46.27944°N 119.26750°W |
| Length | 45 mi (72 km) |
| Basin | 96,000 sq mi (248,639 km2) |
| Discharge | for below Priest Rapids Dam |
| - average | 118,400 cu ft/s (3,353 m3/s) |
| - max | 547,400 cu ft/s (15,501 m3/s) |
| - min | 20,000 cu ft/s (566 m3/s) |
The Hanford Reach is a free-flowing section of the Columbia River, around 51 miles (82 km) long, in eastern Washington state. It is named after a large northward bend in the river's otherwise southbound course. It is the only section of the Columbia in the U.S. that is not tidal nor part of a reservoir, excluding a short reach between the U.S.-Canada border and the upper end of Franklin Delano Roosevelt Lake, the reservoir of Grand Coulee Dam. Much of the Hanford Reach flows through the Hanford Site, a nuclear production facility established during World War II. It is also the site of the Hanford Reach National Monument, created from the original protection area around the Hanford Site. Upstream of the Hanford Reach is Priest Rapids Dam and downstream is the McNary Dam, which also impounds the last stretch of the Snake River, the largest tributary of the Columbia.