Big River, CA has a population of 1,120 and is the 14,459th largest city in the United States. The population density is 103 per sq mi which is 55% lower than the California average and 14% higher than the national average. The median age in Big River is 58 which is approximately 62% higher than the California average of 36. In Big River, 60% of the population over 15 years of age are married, 89% speak English and 9% speak Spanish. 36% of Big River residents were born in California, 57% were born out of state, 1% were born outside of the United States and 6% were foreign born.