with sage-brush, or with extensive salt marshes. The northern table-lands are covered with bunch-grasses suitable for grazing, and here are some junipers and pines. Western Oregon still contains one of the heaviest timber belts in the world. The entire western slope of the Cascades is covered with a belt of forest 20 miles wide, and the Coast Range is also densely forested. In the valleys are found cottonwoods, maple, ash, alder, dogwood, and wild cherry. There are seven species of oak, and the fragrant Oregon myrtle (Oreodaphne Californica) is a common tree. The coniferæ, however, predominate in the large forests, and include pines, spruces, firs, hemlocks, cedars, junipers, larch, and yew. Some characteristic species are the Oregon yellow pine (Pinus ponderosa), the Western arbor-vitæ (Thuya gigantea), the Picea nobilis, and the Oregon yew (Taxus brevifolia). For Fauna, see this section under United States.
Geology. The most remarkable feature of the geological history of Oregon is the enormous volcanic eruption which took place principally in Miocene time, one of the most extensive lava flows in the world. The Cascade Mountains are entirely composed of lava and basaltic rocks, and a lava-sheet 1000 feet thick or more covers the whole eastern two-thirds of the State, together with large parts of Washington and Idaho. Some parts are much weathered and dissected, while others are more recent and smooth. The underlying rock formations are generally shown only where the rivers have cut through the lava. In the Snake River cañon in the northeast the rocks are ancient metamorphic granites, gneisses and mica-slate, while the Cascades are underlaid throughout with Cretaceous rocks covered for some distance (beneath the lava) with Eocene and Miocene strata. In the southwestern valley there is a belt of slates and serpentine, but the Coast Range is mainly an anticlinal whose surface consists of Tertiary sandstone.
Mineralogy and Mining. Oregon has a great wealth and variety of mineral resources, and, curiously enough, some of the richest mineral deposits are found in the valleys. Thus in the serpentine belt in the southwest there are lodes of chrome iron, copper, magnetite, and nickel. The nickel ore exists as a green hydrated nickel-magnesia silicate filling large irregular cavities in the serpentine. The deposit of this is supposed to be very extensive. Limonite, or brown hematite iron ore, is found in the Willamette region, and quartz veins bearing gold and silver occur in the slate belts east of the serpentine as well as in the Cascades and in eastern Oregon, where there are also deposits of zinc and cinnabar. Beds of lignite exist in the Cretaceous and perhaps in the Tertiary strata of the Coast Range, and the sandstones of the latter, as well as the limestones in the south and the volcanic rocks, furnish inexhaustible supplies of building stone. Other minerals found are mercury, platinum, iridium, lead, and antimony, as well as clay, salt, and alkali deposits. Gold is the only mineral extensively mined. It is produced chiefly in the Blue Mountain region in the northeastern part of the State. The annual output has latterly exceeded $1,000,000 in value, reaching $1,694,700 in 1900. Small quantities of silver, borax, and coal are mined, the coal being of the lignite variety.
Fisheries. Salmon fishing and canning is one of the most important industries, and is unequaled by any other State. It began in 1866, and the value of the annual product since 1870 has fluctuated around $2,000,000, the maximum being reached in 1883. Over 5000 people, including many Chinese, have been employed most of this period. For a time reckless overfishing threatened exhaustion of the supply, but the enforcement of laws and the establishment of hatcheries have averted this danger. Sturgeon, halibut, oysters, and other varieties of fish are caught in less quantities. The erection of refrigerating and freezing plants and the increased use of refrigerator cars have made possible greater shipments of fresh fish and have thus tended to lessen the amount of the canned product.
Agriculture. The different sections of the State, varying so distinctly in climate, topography, and soil, naturally vary in agricultural development. In the river valleys west of the Cascades almost every variety of crop common to the temperate zone is produced in great abundance. The Willamette Valley especially is noted for its great productivity. East of the Cascades, in the Columbia Valley, the rainfall is generally sufficient to justify the raising of some of the more hardy crops, the favorable years producing enough to cover the loss in the years of drought. Irrigation is possible in parts of this region and is being resorted to with success. Save in the centre of Oregon there are numerous rivers throughout the eastern half of the State which afford an extensive water supply that could be utilized for irrigation. But these sources have as yet been very little developed, owing largely to the remoteness from lines of transportation and markets. The irrigated area in the State increased from 177,944 acres in 1889 to 388,310 acres in 1899. Almost the whole of this is watered from streams, scarcely any from reservoirs or wells. The largest irrigated area is that north of Malheur and Harney lakes in Harney County. Simple methods are employed in irrigation, and the average cost of it per acre is low. In 1900 only 16.6 per cent. of the land area was included in farms. Of this 33 per cent. was improved. The average size of farms decreased until 1880, since which time, owing to the large additions made to ranges in the eastern part of the State, the average size has grown larger. It has, however, continued to decrease in the western counties.
The two leading crops are wheat and hay. The area devoted to wheat doubled between 1880 and 1900, the increase being almost wholly in the northeast counties, where one-half the crop is now grown. During the same period the acreage of hay and forage gained over threefold. Oats are grown principally in the Willamette Valley, and barley in the northeast counties. Oats have a large acreage. On account of the coolness of the nights, corn does not thrive, and but little is grown. Potatoes produce abundantly and are an important crop. Sugar beets are raised in Union County. The State ranks second in the production of hops, their culture being confined principally to the Willamette Valley. The region between the Cascade and Coast ranges, particularly Jackson and Douglas counties, has become noted for the production of fruit. The number of plum and prune trees in 1900 (2,517,523) was ten times that of 1890 and is only exceeded in California. The number of apple trees
