The legacy of Alta California lives on in the U.S. Southwest

Even the more geographically challenged Americans are familiar with Baja California, if only the border town of Tijuana or the incredible beaches of Los Cabos.

But how many of us know that Baja California is the remnant of a much larger version of California, called Alta California? A territory that once included the modern states of California, Nevada and Utah, along with parts of Arizona, Wyoming, Colorado and New Mexico.

Long before modern-day Baja became host to countless U.S. and international tourists, it existed as part of Alta California, a territory crucial to U.S. history and what we now call the American Southwest. The history of Alta California deserves to be remembered.

In Spanish, baja means low or lower, while alta means high or upper. Thus, Baja California, means lower California. I learned this as a kid, but somehow I always thought that the missing “upper” California was just the state of California as it exists today. That is a common idea that contains a kernel of truth. The modern state of California was certainly part of Alta California. 

But it is only part of the story of Alta California, which traces its legacy to when Spain held sway in the Americas, and much of present-day Mexico and the United States was Spanish territory.

The story begins in 1804, when Spain, which controlled many colonies in the Americas, including what would become Mexico, formally established Alta California, also known as Nueva California, as a province of New Spain. Prior to 1804, Baja California and Alta California were part of a single province called Las Californias. 

Territory claimed by Spain as Alta California included large areas east of the Sierra Nevada and Coast Ranges, but the area was vast, and Spain could never supply enough colonists to secure the territory. 

The borders of Alta California, as claimed by Spain, and then Mexico, extended on the western side along the Pacific Ocean from the present border with Mexico to the present border of Oregon. On the eastern side, Alta California extended from about modern-day El Paso in the south to the present-day Utah/Wyoming border. In the north, from the present northern borders of California and Nevada and Utah/Wyoming. On the southern side, the border ran loosely from San Diego to the Colorado River, then along the northern side of the Gila River, through present-day Arizona into New Mexico and then on to El Paso.

When Mexico gained independence from Spain in 1821, the region became a territory of Mexico. In 1824, the Mexican government made the name Alta California official. At that time, most interior areas such as the San Joaquin Valley and the California desert country remained untouched by outside influence. Those parts of Alta California were populated, if at all, by Native Americans and descendants of ethnic Spanish settlers. That changed around mid-century as the Mexican government increased the number of land grants, and European Americans flowed in. 

Alta California remained separate from Baja California until 1836, when Mexican constitutional reforms, called the Siete Leyes, or Seven Laws, re-joined Baja and Alta California into a single, more independent department called Las Californias.

By 1841, overland immigrants from the United States began to settle the formerly untouched inland areas of Alta California in earnest. With the election of President James Polk in 1844, the days of Alta California were numbered. The United States embarked on a path that became known as Manifest Destiny, and moved to occupy a portion of Texas that had declared independence from Mexico in 1836, but was still claimed by Mexico. This and other actions helped pave the way for the Mexican-American War, with the United States prevailing.

An 1846 map by S. Augustus Mitchell, as seen on the Wikipedia page for Manifest Destiny, labels the area as “Upper” or “New California,” and shows the boundaries of Alta California as they were before it was ceded to the United States in the Treaty of Guadalupe-Hidalgo, which ended the Mexican-American War in 1848. 

Two years later, California joined the union as the 31st state. Other parts of Alta California were broken into Utah Territory in the north, and New Mexico Territory in the South. Eventually these territories became all or part of the present states of Nevada, Utah, Arizona, New Mexico, Colorado and Wyoming.

Today, when people traveling through the southwestern United States are amazed at its rich and diverse cultural history, the blend of Hispanic, Native American and other cultures, and the distinct cuisine and the folklore, they are experiencing part of the legacy of Alta California. It is a heritage and history worth remembering.