L. R. Hafen, Recollections of a Handcart Pioneer (an account of the 1846-1847 Trek to Salt Lake City).

The emigrants were entirely ignorant of the country and climate But Levi Savage used his common sense and his knowledge of the country. He declared positively that we could not cross the mountains with a mixed company of aged people, women, and little children, so late in the season without much suffering, sickness, and death. He therefore advised going into winter quarters without delay; but he was rebuked by the other elders for want of faith Savage was accordingly defeated, as the majority were against him....
Cold weather, scarcity of food, lassitude and fatigue from over-exertion, soon produced their effects... We soon thought it unusual to leave a camp-ground without burying one or more persons.

Death was not long confined to the old and infirm, but the young and naturally strong were among its victims. . . . Weakness and debility were accompanied by dysentery. This we could not stop or even alleviate, no proper medicine being in the camp; and in almost every instance it carried off the parties attacked.