One of their stations was at the Dalles of the Columbia.

In 1835 the great missionary, Marcus Whitman, of the Congregationalist Board, established the mission at Walla Walla.

Yet up to the year 1841, just fifty years ago, only about one hundred and fifty Americans, in all, had permanently settled in Oregon and Washington.
Senator Benton desired the survey of a route to Oregon, to aid emigration to the Columbia basin.

He engaged for this service a young, handsome, gallant, and chivalrous officer, Lieutenant John C.Fremont, who, with Nicollet, a French naturalist, had been surveying the upper Mississippi, and opening emigration to Minnesota.
Fremont espoused not only the cause of Oregon, but also Senator Benton's young daughter Jessie, who later rendered great personal services to her husband's expedition in the Northwest.
Kit Carson was the guide of this famous expedition.

The South Pass was explored, and the flag planted on what is now known as Fremont's Peak, and the country was found to be not the Great American Desert of the maps, but a land of wonderful beauty and fertility.