The average household size was 2.30 and the average family size was 2.33. The age distribution was 30.4% from 25 to 44, 39.1% from 45 to 64, and 30.4% 65 or older. The median age was 60 years. For every 100 females, there were 155.6 males. For every 100 females age 18 and over, there were 155.6 males. The census-designated place is just downstream from the Grizzly Valley Dam, which impounds Lake Davis. In the state legislature, Lake Davis is in , and . Federally, Lake Davis is in . Little Grass Valley, California  Little Grass Valley is a census-designated place in Plumas County, California, USA. As of the 2010 census, it had a total population of 2. According to the United States Census Bureau, the town has a total area of . Although the Bureau states there is no water, the lake covers about 1600 acres (6.5 km² or 2.5 sq mi). The 2010 United States Census reported that Little Grass Valley had a population of 2. The population density was 0.2 people per square mile (0.1/km²). The racial makeup of Little Grass Valley was 2 (100.0%) White, 0 (0.0%) African American, 0 (0.0%) Native American, 0 (0.0%) Asian, 0 (0.0%) Pacific Islander, 0 (0.0%) from other races, and 0 (0.0%) from two or more races. Hispanic or Latino of any race were 0 persons (0.0%). The Census reported that 2 people (100% of the population) lived in households, 0 (0%) lived in non-institutionalized group quarters, and 0 (0%) were institutionalized. There were 1 households, out of which 0 (0%) had children under the age of 18 living in them, 1 (100%) were opposite-sex married couples living together, 0 (0%) had a female householder with no husband present, 0 (0%) had a male householder with no wife present. There were 0 (0%) unmarried opposite-sex partnerships, and 0 (0%) same-sex married couples or partnerships. 0 households (0%) were made up of individuals and 0 (0%) had someone living alone who was 65 years of age or older. The average household size was 2.00. There were 1 families (100% of all households); the average family size was 2.00.