Tree Removal in Union, CA.

The Wiyot people and Yurok people inhabited this area prior to the arrival of Europeans, and continue to live in the area. “Kori” is the name for the Wiyot settlement that existed on the site of what would become Arcata. The name “Arcata” comes from the Yurok term oket’oh, meaning “where there is a lagoon” (referring to Humboldt Bay), from o-, “place”, plus ket’oh, “to be a lagoon”. The same name was also used by the Yuroks for Big Lagoon. The natives of this region are the farthest-southwest people whose language has Algic roots, a language family shared with the Algonquian. The traditional homeland of the Wiyot ranged from the Little River in the north and continues south through Humboldt Bay (including the present cities of Eureka and Arcata) and then south to the lower Eel River basin. The traditional homeland of the Yurok ranges from Mad River to beyond the Klamath River in the north. Today, Arcata is the headquarters of the Big Lagoon Rancheria tribe, who maintain a 20-acre (81,000 m²) reservation close by. Local Indian tribes operate several casinos in the area. In a coordinated 1860 massacre, significant numbers of Wiyot people were killed at several locations in and around Humboldt Bay, including the center of their society, the island known to them as Duluwat Island. A local newspaper editor, who would later be known as Bret Harte, was forced to leave the Humboldt Bay area after he editorialized his disgust with the incident.

The Spaniards claimed the area but never settled it; the first permanent settlements occurred after California was admitted to the Union. Arcata was first settled as Union in 1850. Union was created as a port, and reprovisioning center for the gold mines in the Klamath, Trinity, and Salmon mountains to the east, and was very briefly the county seat during this period. It was slightly closer to the mines than Eureka, which gave Union an early advantage. What was to become the first significant town on Humboldt Bay began as Union Company employees laid out the plaza and first city streets in the Spring of 1850. By later in the 1850s redwood timber replaced the depleted gold fields as the economic driver for the region and Eureka became the principal city on the bay due to its possession of the better harbor, gaining it the county seat by the end of the decade.

The Union town post office opened in 1852, and the town changed its name to Arcata in 1860.