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
Many other trails followed the Oregon Trail for much of its length, including the Mormon Trail from Illinois to Utah; the California Trail to the gold fields of California; and the Bozeman Trail to Montana. Because it was more a network of trails than a single trail, there were numerous variations with other trails eventually established on both sides of the Platte, North Platte, Snake, and Columbia rivers. With literally thousands of people and thousands of livestock traveling in a fairly small time slot the travelers had to spread out to find clean water, wood, good campsites, and grass. The dust kicked up by the many travelers was a constant complaint, and where the terrain would allow it there may have been between 20 and 50 wagons traveling abreast.