Moapa Valley
Clark County, Clark County, Nevada
Marker Inscription
Moapa Valley. Rich in Pueblo-type culture, and noted by the explorer Jedediah Smith in 1826, Moapa Valley is crossed by the Old Spanish Trail.In 1865, Brigham Young sent 75 families to settle the area, to grow cotton for the people of Utah, and to connect Utah with the Pacific Ocean via the Colorado River.Located near the junction of the Muddy and Virgin Rivers, and now under Lake Mead, the “cotton mission” was named St. Thomas for its leader, Thomas Smith. Mormons built a prosperous, self-contained agricultural industry in the valley, which included orchards, vineyards, cotton, grains, and vegetables.The December 1870 survey placed the valley in Nevada, which meant property owners owed back taxes to Nevada. The settlers, now including those in St. Joseph, (old) Overton, West Point, and Logandale, began leaving two months later. They abandoned the results of 7 years of labor, more than 18 miles of irrigation canal, and several hundred acres of cleared land.Other Mormons resettled the land in 1880. The area remains one of the most agriculturally productive in the state.
Erected by Southern Nevada Historical Society
The Story
Long a home to Puebloan farming peoples and noted by trapper Jedediah Smith in 1826, the Moapa Valley near the junction of the Muddy and Virgin Rivers drew Mormon settlers in 1865. Sent by Brigham Young to grow cotton and open a Colorado River route to the Pacific, they built the "cotton mission" of St. Thomas and raised orchards, vineyards, grain, and cotton. When an 1870 survey placed the valley in Nevada and saddled residents with back taxes, they abandoned years of labor and miles of canals. Others returned in 1880, and the valley remains among Nevada's most productive farmland.
Why it matters
The valley's story captures how boundary lines and taxes could unmake a frontier community overnight, and how irrigation turned desert into one of the state's agricultural heartlands.
The story behind this marker
AI contextThe era
Where the Muddy and Virgin Rivers meet, the desert relents. Water gathers, soil turns fertile, and for centuries this valley supported farming peoples long before any explorer wrote it down. It was rich in a Puebloan-style culture — communities that raised crops in the arid Southwest and left their mark on the land. When the trapper and explorer Jedediah Smith passed through in 1826, he was among the first Americans to note a valley that its earlier inhabitants had known intimately.
By the 1860s, this ground had another distinction: the Old Spanish Trail crossed it, tying the valley into the wider web of Southwestern travel and trade. It was a natural place to settle — water, workable land, and a route already in use — which is exactly what drew the attention of Mormon leaders looking to extend their reach.
The era was one of ambitious colonization. In the years around the Civil War, the church in Utah pushed settlements outward to grow crops it could not raise at home and to open new routes to the wider world. This valley, remote as it was, fit squarely into those plans.
People & events
In 1865, Brigham Young sent 75 families to settle the valley with two goals: grow cotton for the people of Utah, and connect Utah to the Pacific by way of the Colorado River. They named their "cotton mission" St. Thomas, after its leader, Thomas Smith. It was a bold undertaking in a demanding place.
And for a time, it worked. The settlers built a prosperous, self-contained agricultural community, raising orchards, vineyards, cotton, grains, and vegetables. Soon they were joined by others in nearby St. Joseph, old Overton, West Point, and Logandale. They dug more than 18 miles of irrigation canal and cleared several hundred acres — the patient, backbreaking infrastructure that turns desert into farmland.
Then a survey undid them. In December 1870, the boundary line placed the valley inside Nevada, which meant the settlers suddenly owed back taxes to a state they had not thought they lived in. Within two months they began to leave, abandoning seven years of labor — the canals, the cleared fields, the orchards they had coaxed from dry ground. The valley did not stay empty long: other Mormons resettled it in 1880, and it endures today as one of the most agriculturally productive areas in the state.
Its place in the American story
The Moapa Valley tells a truth about the American West that is easy to forget: that lines on a map, drawn far away, could make or unmake a community overnight. These settlers had done everything asked of them — built canals, raised crops, founded towns — only to have a surveyor's boundary and a tax bill send them packing. Few stories capture so cleanly how fragile frontier life could be, and how much it depended on decisions made elsewhere.
It is also a chapter in the larger epic of Western irrigation. Across the arid West, the difference between empty desert and thriving farmland was water, patiently channeled by human hands. The 18 miles of canal dug here embody that struggle — and the valley's revival after 1880, and its productivity today, show that the effort was not wasted, only interrupted.
And it layers the deep past onto the recent: a valley farmed by Puebloan peoples, noted by an early American explorer, crossed by an old trade trail, and finally settled, abandoned, and settled again. That long human story, all rooted in the same fertile ground, is the American Southwest in a single valley.
If you visit
This is a place to think about water and time. Look at the fertile farmland spread near the meeting of the rivers, and remember that its green owes everything to irrigation — to canals dug by hand more than 150 years ago and to the resettlers who took up the work again. In a desert, cultivated land is never an accident.
Know, too, that some of this story now lies underwater. The original sites near the river junction were later covered by the waters of Lake Mead, so part of what the marker describes has literally vanished beneath a reservoir. That absence is part of the place's poignancy — layers of history, some visible, some submerged.
As a road-trip stop, the valley rewards a slower eye. Take in the productive fields and imagine the families who cleared them, lost them to a boundary line, and whose successors made the desert bloom again. It's a quiet lesson in persistence, and in how much of the West was won not by conquest but by the patient labor of turning dry ground green.
Written by AI to add context, grounded in the marker’s inscription and the historical record. The inscription above is the original, unaltered text.
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Related people
- · Jedediah Smith
- · Brigham Young
- · Thomas Smith
Themes & tags
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