In 2010, there were 1,146 people, 385 households and 310 families living in Plains. The population density was . 88.1% of the people were White, 0.3% were African American, 1.0% were Native American, 0.4% were Asian, 8.5% were from other races, and 1.7% were from two or more races. 36.0% of the people were Hispanic or Latino of any race.