| Big Wood River | |
| Pushpin Map: | USA#Idaho |
| Pushpin Map Size: | 250 |
| Pushpin Map Caption: | Location in the United States##Location in Idaho |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Idaho |
| Subdivision Type3: | Region |
| Subdivision Name3: | Blaine, Lincoln, and Gooding counties |
| Subdivision Type5: | Cities |
| Subdivision Name5: | Sun Valley, Ketchum |
| Length: | 137miles |
| Discharge1 Location: | below Magic Reservoir[1] |
| Discharge1 Min: | 0cuft/s |
| Discharge1 Avg: | 464cuft/s[2] |
| Discharge1 Max: | 9800cuft/s |
| Source1: | Sawtooth Range |
| Source1 Location: | Galena Summit, Blaine County |
| Source1 Coordinates: | 43.8606°N -114.7133°W |
| Source1 Elevation: | 9100feet[3] |
| Mouth: | Malad River |
| Mouth Location: | Gooding County |
| Mouth Coordinates: | 42.945°N -114.7956°W |
| Mouth Elevation: | 3460feet |
| Tributaries Left: | North Fork Big Wood River, East Fork Wood River |
| Tributaries Right: | Camas Creek (Big Wood River) |
The Big Wood River is a 137adj=midNaNadj=mid[4] river in central Idaho, United States, that is a tributary of the Malad River (which in turn is a tributary to the Snake River and Columbia River).
From its source in the Sawtooth Range near Galena Summit in the Sawtooth National Recreation Area, the Big Wood River generally flows south between the Boulder Mountains to the north, Pioneer Mountains to the east, and the Smoky Mountains to the west. Highway 75 accompanies the river southward from Galena Summit, to an area north of Shoshone. Here, it carved Black Magic Canyon.[5]
The river flows by Sun Valley and Ketchum, where it receives the tributary streams of Warm Springs Creek and Trail Creek. Below Ketchum, it is joined by the East Fork Wood River at Gimlet before passing by the small cities of Hailey and Bellevue. Continuing south, the river enters the Wood River Valley, the northern part of Magic Valley, after which it flows into Magic Reservoir. A tributary stream, Camas Creek, joins the river in Magic Reservoir.
Below Magic Dam, the Big Wood River enters Lincoln County, passing by many lava beds and irrigation canals before entering Gooding County. Just west of Gooding, the Big Wood River joins the Little Wood River to form the Malad River.
Big Wood River's water flow is affected by numerous irrigation reservoirs and canals on the river itself and its tributaries.
Variant names of the Big Wood River, according to the USGS, include Malad River, Malade River, Wood River, Poisonous Beaver River, and Sickley River.