When the claim of the United States to the Oregon territory was being strengthened by occupation, Fremont was sent, at his urgent request, to explore the frontier beyond the Missouri river, and especially the Rocky Mountains in the vicinity of the South Pass, through which the American immigrants travelled.
In 1910 Sheridan (8408) in Sheridan county, Douglas in Converse county and Lander in Fremont county were as important as some of the older towns of the southern part of the state.
Oil has been found in eighteen different districts, the fields being known as follows: - The Carter, Hilliard, Spring Valley and Twin Creek in Uinta county; the Popo Agie, Lander, Shoshone, Beaver and a part of Dutton in Fremont county; the Rattlesnake, Arrago, Oil Mountain and a part of Dutton, Powder river and Salt Creek in Natrona county; part of Powder river and Salt Creek in Johnson county; Newcastle in Weston county; Belle Fourche in Crook county; Douglas in Converse county and Bonanza in Bighorn county.
In 1843 General John C. Fremont with Kit Carson and three others explored the Great Salt Lake in a rubber boat.
The excuses and explanations later given by Fremont - military preparations by the Californian authorities, the imminence of their attack, ripening British schemes for the seizure of the province, etc. - made up the stock account of historians until the whole truth came out in 1886 (in Royce's California).
The mountains are covered with one of the noblest redwood forests of the state - the only one south of San Francisco; two groves, the Sempervirens Park (4000 acres) and the Fremont Grove of Big Trees, 5 m.
Here Stonewall Jackson lay with a small force, and in front of him at the outlet of the valley was Banks, while Fremont threatened him from West Virginia.
During1843-1845John C. Fremont made a series of explorations in this region.
It was a very small, very disingenuous, inevitably an anomalous, and in the vanity of proclamations and other concomitant incidents rather a ridiculous affair; and fortunately for the dignity of history - and for Fremont - it was quickly merged in a larger question, when Commodore John Drake Sloat (1780-1867) on the 7th of July raised the flag of the United States over Monterey, proclaiming California a part of the United States.
Mineral springs and hot springs are also a notable feature of Idaho's physiography, being found in Washington, Ada, Blaine, Bannock, Cassia, Owyhee, Oneida, Nez Perce, Kootenai, Shoshone and Fremont counties.