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
Once across the Snake River ford near Old Fort Boise the weary travelers traveled across what would become the state of Oregon. The trail then went to the Malheur River and then past Farewell Bend on the Snake River, up the Burnt River canyon and northwest to the Grande Ronde Valley near present-day La Grande before coming to the Blue Mountains. In 1843 settlers cut a wagon road over these mountains making them passable for the first time to wagons. The trail went to the Whitman Mission near Fort Nez Perces in Washington until 1847 when the Whitmans were killed by Native Americans. At Fort Nez Perce some built rafts or hired boats and started down the Columbia; others continued west in their wagons until they reached The Dalles. After 1847 the trail bypassed the closed mission and headed almost due west to present day Pendleton, Oregon, crossing the Umatilla River, John Day River, and Deschutes River before arriving at The Dalles. Interstate 84 in Oregon roughly follows the original Oregon Trail from Idaho to The Dalles.