The Snake River is a major river of the greater Pacific Northwest region in the United States. At 1,078 miles (1,735 km) long, it is the largest tributary of the Columbia River, in turn, the largest North American river that empties into the Pacific Ocean. The Snake River rises in western Wyoming, then flows through the Snake River Plain of southern Idaho, the rugged Hells Canyon on the Oregon–Idaho border and the rolling Palouse Hills of Washington, emptying into the Columbia River at the Tri-Cities in the Columbia Basin of Eastern Washington.
The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as many of those in the North Cascades, and the notable volcanoes known as the High Cascades. The small part of the range in British Columbia is referred to as the Canadian Cascades or, locally, as the Cascade Mountains. The highest peak in the range is Mount Rainier in Washington at 14,411 feet (4,392 m).
Hermiston is a city in Umatilla County, Oregon, United States. Its population of 19,973 makes it the largest city in Eastern Oregon. Hermiston is the largest and fastest-growing city in the Hermiston-Pendleton Micropolitan Statistical Area, the eighth largest Core Based Statistical Area in Oregon with a combined population of 92,261 at the 2020 census. Hermiston sits near the junction of I-82 and I-84, and is 7 miles south of the Columbia River, Lake Wallula, and the McNary Dam. The Hermiston area has become a hub for logistics and data center activity due to the proximity of the I-82 and I-84 interchange, Pacific Northwest fiber optic backbone, and low power costs. The city is also known for its watermelons, which are part of its branding.
Umatilla is a city in Umatilla County, Oregon, United States. The population in 2010 was 6,906, but the city's population includes approximately 2,000 inmates incarcerated at Two Rivers Correctional Institution.
Hells Canyon is a ten-mile-wide (16 km) canyon in the Western United States, located along the border of eastern Oregon, a small section of eastern Washington and western Idaho. It is part of the Hells Canyon National Recreation Area which is also located in part of the Wallowa-Whitman National Forest. It is North America's deepest river gorge at 7,993 feet (2,436 m), running deeper than the Grand Canyon in Arizona.
The Rogue River in southwestern Oregon in the United States flows about 215 miles (346 km) in a generally westward direction from the Cascade Range to the Pacific Ocean. Known for its salmon runs, whitewater rafting, and rugged scenery, it was one of the original eight rivers named in the Wild and Scenic Rivers Act of 1968. Beginning near Crater Lake, which occupies the caldera left by the explosive volcanic eruption and collapse of Mount Mazama, the river flows through the geologically young High Cascades and the older Western Cascades, another volcanic province. Further west, the river passes through multiple exotic terranes of the more ancient Klamath Mountains. In the Kalmiopsis Wilderness section of the Rogue basin are some of the world's best examples of rocks that form the Earth's mantle. Near the mouth of the river, the only dinosaur fragments ever discovered in Oregon were found in the Otter Point Formation, along the coast of Curry County.
The Walla Walla River is a tributary of the Columbia River, joining the Columbia just above Wallula Gap in southeastern Washington in the United States. The river flows through Umatilla County, Oregon, and Walla Walla County, Washington. Its drainage basin is 1,758 square miles (4,550 km2) in area.
The Columbia Plateau is a geologic and geographic region that lies across parts of the U.S. states of Washington, Oregon, and Idaho. It is a wide flood basalt plateau between the Cascade Range and the Rocky Mountains, cut through by the Columbia River.
McNary Dam is a 1.4-mile (2.2-km) long concrete gravity run-of-the-river dam which spans the Columbia River. It joins Umatilla County, Oregon with Benton County, Washington, 292 miles (470 km) upriver from the mouth of the Columbia. It is operated by the U.S. Army Corps of Engineers' McNary Lock and Dam office. The dam is located a mile (2 km) east of the town of Umatilla, Oregon, and 8 miles (13 km) north of Hermiston, Oregon. The dam was originally planned to be named Umatilla Dam, but the Flood Control Act of 1945 renamed the dam in honor of Senator Charles L. McNary of Oregon, who had died the previous year.
Rooster Rock State Park is a state park located east of Corbett, in the U.S. state of Oregon. One of the features of the park is Rooster Rock, a column of basalt forming a natural obelisk, which stands near the south side of the Columbia River Gorge, in the lee of Crown Point. The park is administered by the Oregon Parks and Recreation Department.
U.S. Route 730 (US 730) is an east–west United States Highway, of which all but 6.08 miles of its 41.78 miles are within the state of Oregon. The highway starts in rural Morrow County in Eastern Oregon at an interchange with Interstate 84 (I-84) and US 30, located east of the city of Boardman. US 730 travels east along the Columbia River as a continuation of Columbia River Highway No. 2 into Umatilla County, intersecting I-82 and US 395 in the city of Umatilla. US 730 and US 395 form a short concurrency within the city before the highways part, with US 730 continuing northeast into Washington. The highway travels through rural Walla Walla County and ends at an intersection with US 12 south of Wallula.
Wallula Gap is a large water gap of the Columbia River in the northwest United States in southeast Washington. It cuts through the Horse Heaven Hills basalt anticlines in the Columbia River Basin, just south of the confluence of the Walla Walla and Columbia rivers.
The Umatilla River is an 89-mile (143 km) tributary of the Columbia River in northern Umatilla County, Oregon, United States. Draining a basin of 2,450 square miles (6,300 km2), it enters the Columbia near the city of Umatilla in the northeastern part of the state. In downstream order, beginning at the headwaters, major tributaries of the Umatilla River are the North Fork Umatilla River and the South Fork Umatilla River, then Meacham, McKay, Birch, and Butter creeks.
The Horse Heaven Hills are a long range of high, rolling hills in Klickitat, Yakima, and Benton counties in Washington. The hills are an anticline ridge in the Yakima Fold Belt formed by north–south compression of lava flows in the Columbia River Basalt Group. The highest point is Bickleton Ridge in the west end of the hills. They lie within the rain shadow to the east of the Cascade Range, making them significantly drier and hotter than regions west of the Cascades.
The Crooked River is a tributary, 125 miles (201 km) long, of the Deschutes River in the U.S. state of Oregon. The river begins at the confluence of the South Fork Crooked River and Beaver Creek. Of the two tributaries, the South Fork Crooked River is the larger and is sometimes considered part of the Crooked River proper. A variant name of the South Fork Crooked River is simply "Crooked River". The Deschutes River flows north into the Columbia River.
Lake Wallula is a reservoir on the Columbia River in the United States, between the U.S. states of Washington and Oregon. It was created in 1954 with the construction of McNary Dam. It reaches from McNary Dam near the city of Umatilla, Oregon, to the Tri-Cities of Washington.
Unity Lake State Recreation Site is a state park in the U.S. state of Oregon, administered by the Oregon Parks and Recreation Department.
The Ice Age Floods National Geologic Trail is a network of routes connecting natural sites and facilities that provide interpretation of the geological consequences of the Glacial Lake Missoula floods of the last glacial period that occurred about 18,000 to 15,000 years ago. It includes sites in Washington, Oregon, Idaho, and Montana. It was designated as the first National Geologic Trail in the United States in 2009.
