SACRAMENTO, Calif. (KTXL) — Cities and communities that make up the modern Sacramento Valley, including the city of Sacramento, probably would not exist had it not been for the mighty river that runs down Central California.

The Sacramento River has provided the resources necessary for the cities and settlements that are at or near its banks, including the Native American tribes that inhabited the area for thousands of years.

Below are some key factors that make the Sacramento River an essential artery for California.

The Largest River in California

Stretching some 384 miles from its origin near Mount Shasta to its terminus in the Sacramento-San Joaquin Delta, the Sacramento River is the largest river in the Golden State.

According to the Water Education Foundation, the Sacramento River provides 31 percent of the state’s surface water runoff.

The Sacramento collects water from the Klamath Mountains, the Cascade Range, the Coast Range and the western slopes of the northern Sierra Nevada.

The runoff from these mountain ranges feeds into the Pit River, McCloud River, a dozen smaller rivers and 10,000 springs and creeks to fill the Sacramento River, according to the Northern California Water Association.

Due to this mass amount of water, the Sacramento River is the second-largest contiguous river by discharge in the U.S. to flow into the Pacific, behind only the Columbia River in Washington state.

12,000 years of human interaction

Before Spanish explorer Gabriel Moraga arrived in the Sacramento Valley in 1808 and named the river Rio de Los Sacramentos (River of the Sacraments), several Native American tribes were settled along its banks.

For centuries, the Miwok, Maidu and Nisenan lived along the lengthy and bountiful river in relative peace, according to Sacramento Historic Sites Association archivist Steve Beck.

“If a group lived north of the river they did not bother the group south of the river because everyone had access to the same resources, but that is not to say there was perfect harmony,” Beck writes.

There were hundreds of villages scattered along the river, with populations ranging from a few dozen to several hundred people living in a village, according to Beck.

“War and killing were not intrinsic to the Valley culture,” Beck writes. “Unlike other North American natives who honored bravery and death in battle, such as the Sioux and the Apache, to the people of the Valley there was no concept of military bravery, and death was simply being dead.”

This peace among the area’s native people was broken as Spanish missionaries began making their way north through California, killing many people as they moved to take control of the land.

The Gold Rush in 1848 would only make matters worse for the Sacramento River’s indigenous inhabitants. As California’s population swelled during the 1850s, many towns along the river grew rapidly. The city of Sacramento itself became a key waypoint for miners on their way from San Francisco to the gold fields in the Sierra Foothills.

Many miners realized money could be made far more easily farming, running a business in town or working at one of the city’s many ports. The river, now filled with keel boats, skips, barges and paddle boats, was bustling with commerce and industry of all sorts as it provided a much needed connection to San Francisco.

The gold, timber, livestock, agriculture and canned goods coming from across the Sacramento Valley were loaded onto riverboats at the port of Sacramento and sent down river to the Bay Area and parts unknown.

The river became the lifeblood for growing farming communities along its banks that would feed the region and place the Sacramento Valley on the map as an agricultural hub in California and the American West.

Far north, near the birth of the Sacramento River, the city of Redding grew along its banks. As rail lines made their way into the town, and mining and farming began to grow, the people of Redding decided that it was time to gain control of the Sacramento and its propensity to flood.

The Shasta Dam was completed in 1944 with a height greater than the Washington Monument at 602-feet-high. Its spillways are three times the height of Niagara Falls.

Today, Shasta Dam is the crown jewel of the Central Valley Project, designed to provide flood control in Northern California and a source of water for Southern California.

Largest watershed in California

The watershed covers 27,000 square miles and supports a population of over 2 million people.

A watershed is all of the land that drains into the same location or body of water. This can include rivers, creeks, lakes, wetlands, farms, forests, farmlands and more.

The watershed lies between the Sierra Nevada and Cascade Range on the east and the Coast Range and the Klamath Mountains in the west.

Agriculture dominates much of the watershed area, covering 2.1 million acres. Rice, fruit and nut trees, grains and hay crops make up the major items in the area, according to the United States Environmental Protection Agency.

Whales and sea lions in the river

As the river ends in the Suisun Bay, hungry marine animals have on occasion found their way into the Sacramento River.

On May 14, 2007, two humpback whales were found near Rio Vista, about 30 miles north of Suisun Bay. The pair, believed to be a mother and calf, made their way 90 miles inland into the deep water channel near West Sacramento, where onlookers said it looked like each whale had been injured by a ship’s propeller or keel.

The two whales were injected with antibiotics from biologists and over the next several days, efforts were made to get the whales to head downriver. The whales eventually returned to the San Francisco Bay, where they stayed for several days before leaving on May 30, 2007.