Big River is a census-designated place in San Bernardino County, California, located on the west bank of the Colorado River at the state's eastern border with Arizona. The community sits in the Sonoran Desert landscape of southeastern California, near the small community of Earp and roughly across the river from the Arizona town of Parker. Its name is fittingly literal: the Colorado River, one of the great waterways of the American West, forms the community's eastern edge and defines its identity. The population of Big River was recorded at 1,084 in the 2020 census, a decline from 1,327 in 2010, reflecting the small and somewhat transient nature of the community. Many of its residents are part-time, using their homes as seasonal bases for river recreation, while a smaller number live there year-round. The community is characterized as semi-private and waterfront-oriented, with direct access to the Colorado River for boating, fishing, water-skiing, and swimming. Big River's remoteness is central to its character. It lies far from the major population centers of Southern California, and the nearest substantial town for supplies, services, and medical care is Parker, Arizona, just across the river. The broader region is anchored by the Colorado River's chain of reservoirs and recreation areas, which draw boaters and vacationers from across the Southwest. For those who choose to live there, Big River offers a quiet, sun-drenched desert lifestyle centered on the river, with wide-open space, warm winters, and a pace of life that stands in sharp contrast to the coastal cities of California.