It is one of the many communities of the Black Hills Indian Reservation. Calexico is a border town. Mexicali, Mexico is across the border. Mexicali is a much larger city. According to the 2010 census, the population of Calexico is 38,572. Mexicans account for 96.8% of the population. The white population can't be correctly calculated. There are 10,651 housing units. The average household size is 3.6 persons per housing unit. Elevation is 3 feet above sea level. Zip codes are 92231 and 92232. Below are several google earth photos of Calexico.