Alturas is the county seat of Modoc County. Located in the Shasta Cascade region of Northern California, the city had a population of 2,715 at the 2020 census. Alturas is located at the confluence of the south and north forks of the Pit River, east of the center of Modoc County, at an elevation of 4,370 feet (1,330 m). Alturas is one of the largest cities in the region and a local economic hub.
Alturas occupies what was initially an Achumawi (Pit River) village known as Kosealekte or Kasalektawi. The city was initially known as Dorris Bridge or Dorris' Bridge, named after Pressley and James Dorris, who built a bridge across the Pit River at this location.
The Dorris Bridge post office opened in 1871. The town was renamed Dorrisville in 1874 and Alturas in 1876, the latter meaning "heights" in Spanish. The census of 1880 showed a population of 148. Settlement continued over the next two decades, until the city was incorporated in 1901. Because of its central location, Dorrisville became the county seat when Modoc County formed in 1874, even though both Adin and Cedarville were then larger towns.
Alturas straddles the North Fork of the Pit River, near its confluence with the South Fork in the north end of South Fork Valley, in the extreme northeastern corner of California at 41°29′14″N 120°32′33″W. The tall Warner Mountains lie to the east, the wetlands and wild rice fields of South Fork Valley to the south, and the extensive Modoc Plateau to the north.