During the years 1833-35 the Rev. Samuel Parker, a zealous missionary, made several haz ardous journeys from the Mississippi waters to those of the Columbia. At this time the Hud son Bay Company, which had absorbed its rival, the Northwestern Company, controlled the en tire Columbia River basin and claimed it for England, in spite of the protest of the few American settlers. In 1842 it came to the knowledge of the Americans that the English were maldng preparations to colonize the region and it was necessary that the authorities at Washington should be informed at once. For this purpose Dr. Marcus Whitman and A. L. Lovejoy set out in the dead of winter on a journey of 4,000 tniles across the continent. They took a southerly route through New Mexico to the Arlcansas, and Whitman reached Washing ton.
In 1841 Lieut. R. E Johnson of the United States Exploring Expedition, commanded by Charles Wilkes, U. S. N., crossed the Cascade Mountains near Mount Rainier and, after mak ing an extended journey in the Columbia River Valley, recrossed the Cascades to the coast. A detachment ascended the Willamette and crossed to the Sacramento Valley, which they followed to San Francisco.
With the exception of the Lewis and Clark expedition, the most important exploration of the century was done by Lieut. John C. Fremont, who had gained his first expenence while assist ing J. N. Nicollet, a French geodesist, employed by the United State.s government 1836-40, for malting surveys in the upper Mississippi Basin. In 1842 Fremont, with 25 men, among whom was the famous scout, Kit Carson, made sur veys of a region lying between the Missouri River and the Rocky Mountains. along the valleys of the ICansas and Great Platte rivers. In 1843 he was instructed to carry his surveys to the Pacific Coast. With a party of 40 men he made his way westward from the junction of the Kansas and Missouri rivers to the head waters of the North Platte, crossed to Green River, and traversing a region long known through the explorations of Bonneville and others, crossed another divide and descended Bear River to Salt Lake, which he explored. From there he went westward to the Snake River, and on to the mouth of the Columbia. After renewing the supply of provisions, Fremont retraced his steps to the Dalles of the Columbia, then turned southward to Klamath Lake, and niade a hazardous journey through the Sierras which brought him into California along the valley of the Aznerican River, an eastern branch of the Sacramento. Traveling southward, he once more crossed the Sierras in lat. 35°,
and returned to Saint Louis across the Great Basin region and the Rockies. On his third journey Fremont crossed the Rockies from the head of the Arkansas to the Green River Valley, then continued westward around the southern end of Salt Lake across the Sierras, near where he previously traversed them and then turned northward along the Sacramento Valley and across the mountains to Klamath Lake. Here he was impelled to turn back by the news of the uprising in California, and converted his exploring party into a military expedition.
The southwest became better known through military operations during the Mexican War, and after its close many expeditions were sent out by the government, under both military and civilian leadership, most of them, however, in regions already explored.
Public interest in the construction of a trans continental railway led to five extensive expedi tions during the years 1852-57: the first explor ing along the 32d parallel; the second near the 35th; the third near the 38th and 39th; the fourth near the 41st and 42d; and the fifth near the 47th and 49th. Various military explora tions and surveys were carried on west of the Mississippi up to the outbreak of the Civil War.
In 1869 Maj. J. W. Powell made a daring exploration of the Grand Canon of the Colo rado. With only a few men, in small boats, he followed the Green and Colorado rivers from Green River Station to the mouth of the Virgin River. In the next two years he extended this exploration in the Colorado basin under gov ernment auspices.
The Pacific Railroad surveys practically com pleted the purely exploratory work of the United States; subsequent investigation was directed to minor details. During the years 1867-79 this work was carried on by various organizations which were created for both geographic and geologic research. Four of them were of special note: °The Geological Exploration of the 40th Parallel," under Clar ence King (King Survey) ; °United States Geographical and Geological Survey West of the 100th Meridians under Capt. Geo. M. Wheeler, U. S. A. (Wheeler Survey) ; °United States Geological and Geographical Survey of Territories,° under F. V. Hayden (Hayden Survey) ; °Geological and Geographical Survey of the Rocky Mountain Region,° under J. W. Powell. In 1879 the United States Geological Survey was created for this purpose and the other organizations discontinued. The acqui sition of Alaska in 1867 gave American ex plorers a new field. See ALASKAN EXPLORA TIONS.