High Quality Content by WIKIPEDIA articles! Walnut Grove is a census-designated place (CDP) in Sacramento County, California, United States. It is part of the Sacramento Arden-Arcade Roseville Metropolitan Statistical Area. The population was 669 at the 2000 census.According to the United States Census Bureau, the CDP has a total area of 3.5 square miles (8.9 km²), of which, 3.1 square miles (8.1 km²) of it is land and 0.3 square miles (0.9 km²) of it (9.86%) is water.As of the census of 2000, there were 669 people, 245 households, and 159 families residing in the CDP. The population density was 214.8 people per square mile (83.1/km²). There were 282 housing units at an average density of 90.5/sq mi (35.0/km²). The racial makeup of the CDP was 49.78% White, 1.49% African American, 3.14% Native American, 21.23% Asian, 0.15% Pacific Islander, 19.13% from other races, and 5.08% from two or more races. Hispanic or Latino of any race were 46.79% of the population.