Personal interest · American history
Mormon Pioneer Trek to the Salt Lake Valley
About 56,000 Latter-day Saints walked and rode the 1,300 miles from Nauvoo, Illinois to the Salt Lake Valley between 1847 and 1868, before the transcontinental railroad finished the route for them in 1869. They made 14–20 miles on a good day. This is who they were, what the journey cost, and how the valley filled.
Who made the trek
Age when they travelled. Those under 25 account for 58% of everyone on the trail.
What took them
Of deaths with a recorded cause, cholera alone accounts for more than half.
“Other” spans dysentery and exposure down to the rare and grim — stampeded, eaten by wolves, murdered.
Men and women died at almost the same rate
Who was most at risk
Mortality runs as a U — teenagers were safest at 1.45%, infants lost 1 in 8, and risk climbed to 1 in 3 for the few who were 80 or older.
Infancy is the deadliest year of life trail or no trail. Published estimates of infant mortality for this period range from roughly 60 to over 200 deaths per 1,000 (6%–20%). The trek’s 127 per 1,000 sits inside that ordinary range — the trail did not invent the risk to infants, it carried it along.
Which company you joined
Company mattered more than method. Wagon and handcart companies lost pioneers at roughly the same rate — but the two companies caught by winter lost 1 in 6.
Share of the company that died, by how you travelled
The two 1856 companies — nearly 39% of all handcart pioneers — that left too late and were caught by winter on the high plains.
The same story across all 307 companies — how many each one lost
- No deaths111
- Up to 5%134
- 5–10%45
- Over 10%17
290 of 307 companies lost fewer than 1 in 10 — Willie & Martin sit in the orange tail of 17 that carried most of the suffering.
Source: Bashore & Tolley, “Mortality on the Mormon Trail, 1847–1868,” BYU Studies 53:4 →
How the valley filled
Running total of pioneers counted onto the trail. By 1868, the year before the railroad finished the route, all 56,042 had set out — and 1,910 of them never arrived.
Mortality, gender, and company-type rates are the published figures from Bashore, Tolley & the BYU Pioneer Mortality Team, “Mortality on the Mormon Trail, 1847–1868” (BYU Studies 53:4) — 56,042 pioneers, 1,910 deaths. The age histogram and cause-of-death shares are reconstructed from the original viz. The annual-arrivals split is also reconstructed — it preserves the original’s year-to-year shape and 1852 peak, rescaled so the running total ends on the study’s 56,042 rather than the original viz’s lower count. Read the yearly figures as shape, not as counts. Original on Tableau →