| Name |
Length |
Watershed size |
Bank |
| Source to Wyoming-Idaho Border |
| Heart River |
8.5 miles (13.7 km) |
|
Right |
| Lewis River |
12 miles (19 km) |
|
Right |
| Gros Ventre River |
642 square miles (1,660 km2) |
|
Left |
| Hoback River |
55 miles (89 km) |
600 square miles (1,600 km2) |
Left |
| Greys River |
65 miles (105 km) |
800 square miles (2,100 km2) |
Left |
| Salt River |
70 miles (110 km) |
890 square miles (2,300 km2) |
Left |
| Snake River Plain to Hells Canyon |
| Henrys Fork (Snake River) |
110 miles (180 km) |
3,212 square miles (8,320 km2) |
Right |
| Portneuf River |
96 miles (154 km) |
1,329 square miles (3,440 km2) |
Left |
| Raft River |
1,506 square miles (3,900 km2) |
|
Left |
| Malad River |
11.5 miles (18.5 km) |
3,000 square miles (7,800 km2) |
Right |
| Salmon Falls Creek |
218 miles (351 km) |
2,082 square miles (5,390 km2) |
Left |
| Bruneau River |
3,305 square miles (8,560 km2) |
|
Left |
| Boise River |
75 miles (121 km) |
4,100 square miles (11,000 km2) |
Right |
| Owyhee River |
280 miles (450 km) |
11,049 square miles (28,620 km2) |
Left |
| Malheur River |
165 miles (266 km) |
4,700 square miles (12,000 km2) |
Right |
| Payette River |
62 miles (100 km) |
3,240 square miles (8,400 km2) |
Right |
| Hells Canyon |
| Weiser River |
90 miles (140 km) |
1,660 square miles (4,300 km2) |
Right |
| Burnt River |
50 miles (80 km) |
|
Left |
| Salmon River |
425 miles (684 km) |
14,000 square miles (36,000 km2) |
Right |
| Grande Ronde River |
212 miles (341 km) |
4,000 square miles (10,000 km2) |
Left |
| Clearwater River |
80 miles (130 km) |
9,645 square miles (24,980 km2) |
Right |
| Idaho-Washington border to mouth |
| Tucannon River |
70 miles (110 km) |
503 square miles (1,300 km2) |
Left |
| Palouse River |
140 miles (230 km) |
3,303 square miles (8,550 km2) |
Right |
