One of ten people who set off on the Oregon Trail did not survive. The biggest causes of death were accidents and disease. The number of deaths is difficult to calculate as most were buried in unmarked graves, but it is estimated that up to 30,000 people died during the 20-year migration along the Trail.
Accidents were caused by gunshots, injuries from animals, drownings, hypothermia, and crush injuries from wagon wheels, which was particularly common among young children.
Infectious diseases caused 6% of all deaths on the Oregon Trail. The disease that caused the most deaths was Asiatic cholera, and was caused by unsanitary conditions of multiple people camping together. It resulted in diarrhea and vomiting. Victims often died within 12-24 hours. Cholera killed up to 3% of all travelers on the Oregon Trail.
Dysentery, Rocky Mountain Spotted Fever and Measles were other infectious diseases that caused deaths along the Trail.
It is estimated that Indians killed 326 Oregon Trail travelers, however the travelers are believed to have killed 426 Indians.