ROCKY MOUNTAINS, THE, a chain of mountains in the central and W. por tions of the North American continent, are a prolongation of the great Mexican Cordillera, extending from the N. fron tier of Mexico N. in several ranges, one of which, the E., passing through British North America, reaches the Arctic ocean in about lat. 70 N.; while the W., pass ing near the Pacific coast, terminates near Prince William's Sound, in about lat. 60° N. The territory occupied extends from the Californian shores of the Pa cific to about Ion. W., or it may be considered as extending 125 miles further E., including the Black Hills of South Dakota and Wyoming. The whole area properly included by the mountains and their intervening valleys and desert lands in the country belonging to the United States is estimated at about 980,000 square miles. The mountainous belt of eastern New Mexico and of the State of Colorado, first met with in crossing the great plains that lie along the head waters of the rivers which flow S. E. into the Mexican Gulf, and E. toward the Mississippi, has a general N. and S. direction. Santa Fe, N. M., is situated on this belt, and further N. it includes territorially the Spanish peaks. On its E. margin stands Pike's Peak, while in Colo rado and Nebraska are those portions of the chain known as the Three Parks, and the Medicine Bow Mountains. From Long's Peak, in about lat. 40°, the range trends N. W., connecting with the Wind River Mountains, which latter includes Fremont's Peak, 13,870 feet above sea level. Beyond that peak to the N. boun dary of the United States the range sepa rates the Dakotas and Washington, and the pass known as Lewis and Clark's, in lat. is the most northern pass of its system in the Union, and is the one fol lowed by the Northern Pacific railroad. In British North America the "Rockies" di vide the waters of the Pacific from those which flow into Hudson Bay, as the Sas katchewan, Athabaska, etc., and also from the Mackenzie river, whose outlet is the Arctic ocean. The next great range of this mountain system toward the W. is that called the Wahsatch Mountains, lying S. from Great Salt Lake, and toward the N. W. this region is traced along the W. bank of the Colorado toward the Sierra Nevada, which forms the E. boundary of California, and the watershed of the Col orado, and Lewis' Fork of the Columbia river, in lat. 37° and 46° respectively. Nearly the whole area between these points, and for a breadth of about 10 degrees of longitude, stretching E. from the Sierra Nevada, is a vast and par tially explored territory, from 4,000 to 5,000 feet above sea-level, which receives the streams that fall on the W. slope of the Wahsatch range and on the E. slope of the Sierra Nevada. In British America this section of the chain interlocks with the main trunk of the Rocky Mountains.
The W. portion of the chain commences at the S. extremity of the Lower Cali fornian peninsula, then passing through California it bifurcates into two ranges, known, respectively, as the Sierra Nevada, at a distance of about 160 miles from the coast, and the Coast Range, skirting the shores of the Pacific from 10 to 50 miles inland, till it reconnects with the Sierra Nevada in northern California, in which section Mount Shasta attains an altitude of about 14,000 feet above tide water. Throughout all of Oregon and Washing ton, the distinction is still maintained be tween the main range (Sierra Nevada), here called the Cascade Mountains, and the Coast Range. The latter traverses the central portion of Vancouver Island for its whole length, and on the mainland in British Columbia the Sierra Nevada proceeds N. and is crossed by the Fraser river. Though the Sierra Nevada in its range between California and Nevada is intersected by no rivers, several of the streams which flow down its E. slopes have their sources high on the summits in the vicinity of those which feed the W. watershed. Several depressions are met with at these points, which serve as passes for the routes from Sonora, Sacra mento, and Marysville to the E. By the canon of Carson river, the range is crossed at an elevation of about 7,250 feet; and by the Truckee Pass the eleva tion is about 6,000 feet. From these passes the route is N. E. to the main road which crosses the Sierra Nevada in the N. portion of California, and which E. passes by the Humboldt Mountains to Salt Lake City. To the E. of Salt Lake this route continues across the Wahsatch range to the great South Pass of the Wind River Mountains, immediately S. of Fre mont's Peak, and thence down the Sweet water to the N. fork of the Platte. A more S. route connects Pike's Peak with the Utah basin, and thence turning S. W. crosses the Sierra Nevada near its junc tion with the Coast Range in northern California, meeting at this point the route from Santa Fe through New Mexico, and the still more S. one from Texas, which follows the valley of the Gila, and crosses that river and the Colorado at their junc tion. Mount St. Elias, in Alaska, is one of the highest peaks of this extensively ramified mountain system, though claimed to be surpassed in height by the neighbor ing Mount Logan. For relative mountain heights, see MOUNTAIN. The mineralogi cal, geological, and botanical character istics of the various ranges of the Rocky Mountains' chain are treated in this work under the names of the several States, Territories, and regions with which it has connection. The Rocky Mountains were first partially explored by Lewis and Clark's expedition in 1804. Subsequently explorations were made by Harman, Long, Schoolcraft, Nicollet, Bonneville, Fre mont, and by many others.