CASCADE MOUNTAINS  , a continuation northward of the Sierra

Nevada, some 500 M. across the states of Oregon and Washington, U.S.A., into British Columbia . In American territory the range lies from loo to 150 M. from the coast.- The Cascades are separated on the S. from the Sierras by deep valleys near Mt . Shasta in California, while on the N., somewhat below the international boundary of 490 N., they approach the northern Rockies, mingling with these in inextricable confusion, although their name is given also to the much-broken, river-dissected, central mountain plateau that crosses British Columbia from S.E. to N.W . Geologically the Sierras and Cascades are very different, though their exact relations are not yet clearly determined; topographically they are also different . The Cascades are in general a comparatively low, broad mass surmounted by a number of imposing peaks in Oregon and Washington . Especially north of the Columbia river, the range widens out into a plateau . There are no notable elevations in British Columbia . Evidences of volcanic activity in comparatively recent geologic time are abundant throughout the length of the range, and all the highest summits are volcanic cones, covered with snow fields and, in a number of instances, with glaciers . The grandest peaks are Shasta (14,380 ft.) at the southern end, and Rainier (or Tacoma, 14,363 ft.) in Washington, two of the most magnificent mountains of America . Other notable summits are Mt . Pitt (076o), Mt . Scott (9122), Diamond Peak (8807), Mt .

Thielsen (9250), Mt .

Jefferson (10,200) and Mt . Hood (11,225), in Oregon; and Stuart (947o), St Helens (ro,000), Baker (10,827) and Adams (12,470), in Washington . The Fraser river in the far north, the Columbia at the middle, and the Klamath in the south cut athwart the range to the Pacific, and many minor streams descend the range to swell their waters, while some drain directly from the flanks of the mountains into Puget Sound and Gray's Harbor . The Columbia has cut almost to the sea-level through the great mountain mass, the Dalles being only about loo ft. above the 'sea . It is to the Cascades of the tremendous rapids at this point that the mountains owe their name . The slopes of the Cascades, particularly on the west, which has a very much moister climate than the eastern slope, are clothed with magnificent forests, chiefly of coniferous evergreens: firs, pine, tamarack and cedar . The Douglas fir, the " Oregon pine " of commerce, often attaining a height of 250 ft., is one of the most beautiful trees in the world . There are also a variety of deciduous trees, but in the aggregate they are unimportant . In 1910 the mountain forests were largely included in ten national forest reserves, with a total area of nearly 16,000,000 acres, extending from the northern boundary of Washington to the southern boundary of Oregon . The magnificent forest cloak, splendid peaks, great open mountain plateau pastures, and exquisite lakes embosomed in mountain fastnesses and forest gloom,. give variety to the scenery, which is often grand, and throughout the range indescribably beautiful, though perhaps not equal to the Sierra Nevada in splended light and colour . Large game—deer, bears, mountain sheep and goats, wolves and panthers—still abound .

Two great railway systems, the Great Northern and the Northern Pacific,

cross the Cascades through noteworthy tunnels; that on the former line is 21 M. long, that on the latter a little less than 2 M . See OREGON and WASHINGTON; also G . O . Smith and F . C . Calkins, A Geological Reconnaissance across the Cascade Range near the Forty-Ninth Parallel (Washington, D.C., 1904), being U.S . Geological Survey Bulletin 253 .