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
In fall of 1823, Jedediah Smith and Thomas Fitzpatrick led their trapping crew south from the Yellowstone River to the Sweetwater River. They were looking for a safe location to spend the winter. Smith reasoned since the Sweetwater flowed east it must eventually run into the Missouri River. Trying to transport their extensive fur collection down the Sweetwater and North Platte River, they found after a near disastrous canoe crash that the rivers were too swift and rough for water passage. On July 4, 1824, they cached their furs under a dome of rock they named Independence Rock and started their long trek on foot to the Missouri River. Upon arriving back in a settled area they bought pack horses (on credit) and retrieved their furs. They had re-discovered the route that Robert Stuart had taken in 1813—eleven years before. Thomas Fitzpatrick was often hired as a guide when the fur trade dwindled in 1840. Jedediah Smith was killed by Indians around 1831.