| Length | Average Discharge | Answer | % Correct |
|---|---|---|---|
| 187 mi | 37,400 ft³/s | Willamette River | 100%
|
| 1,078 mi | 56,900 ft³/s | Snake River | 100%
|
| 115 mi | 3,039 ft³/s | Okanogan River | 50%
|
| 105 mi | 9,140 ft³/s | Cowlitz River | 0%
|
| 252 mi | 5,845 ft³/s | Deschutes River | 0%
|
| 485 mi | 30,650 ft³/s | Kootenay River | 0%
|
| 479 mi | 26,430 ft³/s | Pend Oreille River | 0%
|
| 284 mi | 2,060 | John Day River | 0%
|
| 175 mi | 2,925 ft³/s | Kettle River | 0%
|
| 95 mi | 6,125 ft³/s | Lewis River | 0%
|
| 57 mi | 2,257 ft³/s | Sandy River | 0%
|
| 111 mi | 7,900 ft³/s | Spokane River | 0%
|
| 53 mi | 3,079 ft³/s | Wenatchee River | 0%
|
| 214 mi | 3,542 ft³/s | Yakima River | 0%
|