Cholera outbreaks and pandemics
That year, cholera was transmitted along the California, Mormon and Oregon Trails as 6,000 to 12,000 are believed to have died on their way to the California Gold Rush, Utah and Oregon in the cholera years of 1849–1855. It is believed more than 150,000 Americans died during the two pandemics between 1832 and 1849.
Oregon Trail
Mormon emigration records after 1860 are reasonably accurate, as newspaper and other accounts in Salt Lake City give most of the names of emigrants arriving each year from 1847 to 1868. Gold and silver strikes in Colorado, Idaho, Montana, Nevada, and Oregon caused a considerable increase in people using the trails, often in directions different from the original trail users.