How San Bernardino County Became the Largest County in the Contiguous U.S.

SAN BERNARDINO — Stretching across more than 20,000 square miles, from the edge of the sprawling Los Angeles metropolis in the west to California’s desert border with Nevada and Arizona in the east, San Bernardino County is by far the largest county in the lower 48 states.

It’s bigger in area than nine states, as well as Switzerland, Denmark, Belgium and dozens of other countries, as advocates of a recent push for county secession often point out. You can see on any map of the 58 counties of California that San Bernardino dwarfs all others.

The reason for its vast size? A Mormon settlement that took root in Southern California almost two centuries ago.

In 1851, Brigham Young, the head of the Church of Jesus Christ of Latter-day Saints and the governor of the Utah Territory — it wasn’t yet a state — dispatched an envoy to Southern California to plant a Mormon colony that he hoped would expand the church’s influence, gain converts and chart a snow-free wagon route to transport goods from the Pacific Coast.

According to the historian Edward Leo Lyman, 437 Latter-day Saints, traveling in 150 covered wagons, made the treacherous 600-mile journey from central Utah to Southern California through the rocky Cajon Pass, “undoubtedly one of the most arduous pioneer treks in American history.” (An imposing sandstone outcropping in the pass named the Mormon Rocks honors their voyage, though, of course, Native tribes lived near these rocks for hundreds of years before Spanish or Anglo settlers arrived.)

Upon arriving in California, the Mormon travelers bought a 35,000-acre plot of land known as Rancho San Bernardino from the Lugo brothers, part of a prominent Los Angeles family, said Nathan Gonzales, who teaches history at the University of Redlands. They began to grow their settlement, building houses, devising a street grid and planting fruit trees and vineyards.

At the time, the height of the gold rush, San Francisco was the political center of California — which had just joined the union in 1850 — and the southern half of the state was still referred to as “the cow counties” because of all the undeveloped land, Gonzales told me. The newly formed San Bernardino, about 60 miles east of the city of Los Angeles, fell within the boundaries of Los Angeles County and within a year became its second biggest city.

That gave the Mormon community political power in the region. In 1852, Jefferson Hunt, a well-known Mormon settler, was elected to the California State Assembly — and at the top of his agenda was creating San Bernardino County.

Hunt wanted his new territory to be wide enough to incorporate not just the growing Mormon settlement but also all existing and potential future routes from Southern California to Salt Lake City, which was a goal of Young’s, according to the historian Tom Sutak.

In April 1953, California lawmakers approved Hunt’s proposal to carve out an eastern swath of Los Angeles County to form San Bernardino County.

The county’s trapezoidal boundaries shifted slightly over the next few decades, and a slice was removed to create neighboring Riverside County in 1893. But San Bernardino County has remained California’s biggest county, encompassing much of the Mojave Desert and some of Joshua Tree National Park, with its northeast corner roughly 50 miles from Las Vegas and its southwest 50 miles from the Pacific Ocean.

In downtown San Bernardino, at the palm-tree-lined entrance to a towering county courthouse, a green sign marks the site of the Mormon Stockade, the first place that the Mormon colonists lived when they arrived in California. A 30-minute drive northwest, through a harsh landscape that looks like the set of an old Western, barren but for a few ranch houses and yuccas, I recently spotted the Mormon Trail Monument, an old wooden wheel that points to the nearby mountains, where the pioneers entered — and eventually departed — the San Bernardino Valley.

As the California colony expanded, Young became increasingly concerned that its residents were straying too far from the church, and that some had perhaps become disillusioned with some of its practices, including polygamy. (Hunt, the state assemblyman known as the “Father of San Bernardino County,” had two wives and is believed to have had the most children — 21, as well as 154 grandchildren — of any state legislator in California history, said Jackie Peterson, a California State Library spokesperson.)

In 1857, just six years after his followers arrived, Young recalled the San Bernardino settlers to Utah. His suspicions were at least partially confirmed, according to Lyman, the historian: Of the roughly 3,000 people living in the California settlement at the time, only about half went back to Salt Lake. The rest stayed in San Bernardino.

What we’re eating

Crisp gnocchi with brussels sprouts and brown butter.

Where we’re traveling

Today’s tip comes from Patrice Smerdu:

“The city of Carlsbad is well worth a visit. The old downtown has great restaurants and boutique shops, and Legoland is close by. This time of year, the Flower Fields are a wonderful place to visit and are open until Mother’s Day with almost 50 acres of flowers and other activities.”

Tell us about your favorite places to visit in California. Email your suggestions to CAtoday@nytimes.com. We’ll be sharing more in upcoming editions of the newsletter.

Tell us

What foods do you consider quintessentially Californian? Sourdough bread? Wine? Oranges? California burritos?

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And before you go, some good news

Jay Tracy, an itinerant teacher of the deaf, lives in the Bay Area with his wife and four children — and an extra refrigerator stuffed with pounds of heirloom cucumber seed.

This seed stash represents the product of a yearslong treasure hunt.

In 2009, Tracy, who was living in Tucson, Ariz., at the time, wanted to identify which types of cucumber might perform best in hot and dry environments. He’s since become a foster parent to more than 50 cucumber varieties, many of which look nothing like what you would see in a grocery store.

He’s particularly interested in cucumber melons, which are genetically closer to a cantaloupe or honeydew than a cucumber. Their perk? “They are never bitter,” he said, “and always easy on the digestion.”

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