The Columbia River forms most of the Oregon-Washington boundary, and with its tributaries this great river drains a large portion of Oregon. From the point where the Columbia first touches the state, at Wallula Gap, the river runs in a shallow gorge, deepening as it approaches the Cascades. This part of the river once had many rapids and falls, but is now navigable by large vessels because of dams and locks that have been built along much of its length. An important tributary of the Columbia is the Snake River, which forms part of the Oregon-Idaho boundary. The Snake rises in Yellowstone National Park and flows through Wyoming and Idaho before reaching Oregon. It supplies water for irrigation and power.
The Willamette River, the most important within the state, has its headwaters in the high Cascades, north of Crater Lake. It supplies water for cities and industries in the valley and has become an important amenity. The Deschutes River collects water from the eastern flanks of the Cascade Mountains before joining the Columbia near The Dalles.
The rivers of the northern Oregon coast are short, generally draining only the western side of the Oregon Coast Range, although the Siuslaw and Umpqua rivers traverse the entire range farther south. The Rogue River drains a large area in the southwest of the state.The lakes of Oregon include coastal dune-blocked lakes as well as the lakes of the high Cascades and several shallow basin lakes in the more arid areas.
Oregon’s largest lake is Upper Klamath Lake, which lies on the eastern fringes of the Cascades. In the high Cascades, most of the lakes were formed either by glacial action or by lava flows that dammed up stream valleys.
Water from these lakes is used in lower regions for irrigation and general water supply. Near the crest of the Cascades are two large lakes, Odell and Waldo. Also in the Cascades is spectacular Crater Lake, which is the deepest lake in the United States. In the Wallowa Mountains are several lakes of glacial origin, the largest of which is Wallowa Lake. In south central Oregon, some of the lakes occupy large basins in areas of interior drainage and therefore have a sharply fluctuating water level, depending on the amount of rainfall. On occasion they even dry up. Included in this group are Summer, Abert, Harney, and Malheur lakes.
The coastline of Oregon is regular, with few indentations or promontories. Beaches fringed with low dunes line many parts of the coast. Rugged cliffs and headlands make up the rest of the shoreline. The most important bays are Tillamook Bay, Yaquina Bay, and Coos Bay, the leading ocean harbor for freighters on the Oregon coast. "Oregon" © Emmanuel BUCHOT, Encarta, Wikipedia
Photos of European countries to visit
Photos of Asian countries to visit
Photos of America