| Powder River (Oregon) Port-pel-lah | |
|---|---|
 The Powder River atBaker City | |
  Location of the mouth of the Powder River in Oregon | |
| Native name | Polalle Illahe (Chinook jargon) |
| Location | |
| Country | United States |
| State | Oregon |
| Region | Baker andUnion counties |
| Physical characteristics | |
| Source | Confluence of McCully Fork and Cracker Creek |
| • location | Sumpter, Oregon, in theSumpter Valley Dredge State Heritage Area,Blue Mountains |
| • coordinates | 44°44′30″N118°12′22″W / 44.74167°N 118.20611°W /44.74167; -118.20611[1] |
| • elevation | 4,400 ft (1,300 m) |
| Mouth | Brownlee Reservoir on theSnake River |
• location | 10 mi (16 km) east ofRichland, Oregon |
• coordinates | 44°44′37″N117°02′56″W / 44.74361°N 117.04889°W /44.74361; -117.04889[1] |
• elevation | 2,064 ft (629 m) |
| Length | 153 mi (246 km)[2] |
| Basin size | 1,603 sq mi (4,150 km2)[3] |
| Discharge | |
| • average | 534 cu ft/s (15.1 m3/s)[3] |
| Type | Scenic |
| Designated | October 28, 1988[4] |
ThePowder River is a tributary of theSnake River, approximately 153 miles (246 km) long,[2] in northeastOregon in the United States. It drains an area of theColumbia Plateau on the eastern side of theBlue Mountains. It flows almost entirely withinBaker County but downstream of the city ofNorth Powder forms part of the border between Baker County andUnion County.
The namePowder River is first recorded in the journals ofPeter Skene Ogden without notation of the origin of the name. ExplorerDonald Mackenzie likely named the river. William C. McKay, grandson ofJohn Jacob Astor's partnerAlexander MacKay, says that the origin of the name is from the powdery and sandy soil along the shores of the river, from theChinook Jargonpolalle illahe. It appears onLewis and Clark's maps asPort-pel-lah.[5]
The Powder River's tributaries arise in the southernBlue Mountains in theUmatilla National Forest. The river'smain stem begins inSumpter, where McCully Fork, Cracker Creek and several smaller tributaries join, and flows east-southeast through the tailings of past dredge mining and into Phillips Reservoir. After exiting Phillips Reservoir, the river continues east for about 7 miles (11 km) before turning sharply north through the Bowen Valley and Baker City, Oregon. From here the river meanders the floor of the Baker Valley and passes by the cities ofHaines and North Powder, where it is joined by theNorth Powder River. Here the river turns again sharply east-southeast, flowing through Thief Valley Reservoir, in a valley along the southern edge of theWallowa Mountains. The river then transits the Lower Powder Valley and enters the Snake River on the Idaho–Oregon state line from the west, upstream from the Brownlee Dam at the Powder Arm of Brownlee Reservoir 11 miles (18 km) downstream fromRichland.[6]
Major streams flowing into the Powder areEagle Creek, Wolf Creek, Rock Creek and the North Powder River.[6]
The Powder River watershed drains 1,603 square miles (4,150 km2) of northeastern Oregon.[3] There are three man-made reservoirs on the Powder River: Phillips Reservoir (behind Mason Dam), Thief Valley Reservoir, and also the Powder arm of Brownlee Reservoir at the Oregon–Idaho border at the confluence of the Powder and Snake Rivers.
In 1988, 11.7 miles (18.8 km) of the Powder River was designatedWild and Scenic. Between theThief Valley Dam and theOregon Route 203 bridge, this stretch flows through a rugged canyon with spectacular geologic formations.[7]
Beaver (Castor canadensis) populations are increasing along the river, with an excellent viewing area just offOregon Route 7 belowMason Dam, about 14 miles (23 km) from Baker City. There, a colony of beavers constructed a large dam easily viewed below the footbridge adjacent to the paved parking area. Recovered from near extirpation by theHudson's Bay Company, who tried to create a "fur desert" to discourage Americans from coming to the far western states, benefits of beaver in arid eastern Oregon include creating ponds which along young salmonids to grow, raising the water table as their ponds recharge groundwater supplies and creating wetlands which trap sediment and pollutants.[8]
The Powder River was once an important spawning stream forChinook salmon (Oncorhynchus tshawytscha) andsteelhead trout (Oncorhyncus mykiss) coming from the Pacific Ocean.[6] Chinook salmon once migrated by the thousands to spawn in the Powder River and many of its tributaries from its headwaters to the lower end of the North Powder Valley, but that stopped when the Thief Valley Dam was built nearNorth Powder in 1931. The building of two later dams inHells Canyon on the Snake River – Hells Canyon Dam (1967) andBrownlee Dam also permanently block salmon passage. TheOregon Department of Fish and Wildlife often release Chinook salmon on the Powder River for sportfishing at Mason Dam below Phillips Reservoir.[9]
