OREGON, popularly known as the "Beaver State," is one of the north-western States of the United States of America, lying on the Pacific slope between 42° and 46° 18' N. lat., and 33' and 124° 32' W. longitude. It is bounded on the north by Wash ington, from which it is separated in part by the Columbia river and in part by the 46th parallel, on the east by Idaho, from which it is separated in part by the Snake river, on the south by Nevada and California and on the west by the Pacific ocean, upon which it has a tidal shore line, omitting islands, of 429 miles. It has an extreme length E. and W. of 375m., and extreme width N. and S. of 29om. and a total area of 96,699 sq.m., of which 1,092 sq.m. are water surface. Spanish, French and Indian sources for the name "Oregon" have been suggested but its definite origin is unknown. The first known use of the word is by Major Robert Rogers in his plans for an exploring expedition to the north-west coast in 1767. He applied it to a river flowing into the Pacific ocean of which he had heard and it was later applied to the Columbia river and then to the entire territory drained by the river. Out of this original territory other States were created until only the present area was left to bear the name.
Several small streams, among them the Nehalem, Coquille, Rogue and Umpqua rivers, cut their way through the Coast Range to reach the ocean. For the northern two-thirds of its length in Oregon, the Coast Range is bordered on the east by the Willamette valley, a region about 200M. long and about 3om.
wide, and the most thickly populated portion of the State; here, therefore, the range is easily defined, but in the south, near the Rogue river, it merges apparently with the Cascade and the Sierra Nevada mountains in a large complex group designated as the Klamath mountains, lying partly in Oregon and partly in California, and extending from the northern extremity of the Sierra Nevada to the sea. A number of ridges and peaks bearing
special names, such as the Rogue river, Umpqua and Siskiyou mountains, belong to this group. The Cascade mountains, the most important range in Oregon, extend parallel with the coast and lie about loom. inland. The peaks of this system are much higher than those of the Coast Range, the highest of them being cones extinct volcanoes. Mt. Hood (11,225ft.), the highest i point in the State, Mt. Jefferson (io,2ooft.), the Three Sister Peaks, Mt. Adams, Bachelor mountain and Diamond Peak, all have one or more glaciers on their sides.
The Cascade mountains divide the State topographically into two sharply contrasted parts. West of this range the country exhibits a great variety of surface structure, and is humid and densely wooded; east of the range it consists of a broken table land, arid or semi-arid, with a general elevation reaching 5,000 feet. This eastern tableland, though really very rugged and moun tainous, has few striking topographic features when compared with the more broken area to the west. In the north-eastern part of this eastern plateau lie the Blue mountains, which have an average elevation of about 6,000ft. and decline gradually toward the north. A south-western spur, about loom. in length, and the principal ridge together enclose on several sides a wide valley drained by the tributaries of the John Day river. Draining the eastern slopes of the Cascade Range for the northern two-thirds of its length and flowing into the Columbia a few miles west of the mouth of the John Day river is the Deschutes river, flowing through a valley less arid than the plateau region to the south eastward. South-east of the Deschutes river and south of the Blue mountains lies the Great Basin region. In Oregon this area extends from the Nevada boundary northward for about 16om. and embraces an area of about 16,000 sq. miles. All of its streams lose their waters by seepage or evaporation. Many of the moun tains within the basin region consist of great faulted crust blocks, with a general north and south trend. One face of these mountains is usually in the form of a steep palisade, while the other has a very gradual slope. Between these ridges lie almost level valleys, whose floors consist partly of lava, partly of volcanic fragmental material, partly of detritus from the bordering mountains.