Following a period of working at the site where gold was discovered in California, former members of the Mormon Battalion began their trip eastward to find the main body of members of The Church of Jesus Christ of Latter-day Saints and their families who were working their way to Zion.
Those Mormon Battalion members blazed perhaps 170 miles of new trail through the Sierra-Nevada Mountains that became a popular route for thousands of others headed in the opposite direction to the gold fields. This route went up over Carson Pass, where it intersected with another established California Trail that crossed Donner Summit.
Ironically, historical traditions note that Kit Carson did not discover, nor claim to discover, Carson Pass. In any event, because of earlier routes led by John C. Fremont and his guide, Kit Carson, the Mormon route became known by different names: Old Emigrant Road, Carson River Road, Carson Immigrant Trail or Mormon Carson Immigrant Trail. It was used by some 200,000 travelers.
Because its elevation exceeded 8,600 feet and it had heavy annual snowfall, the trail could be used for only a few months of the year, making traffic heavy.