For statistical purposes, the
United States Census Bureau has defined Rancho Tehama Reserve as a
census-designated place (CDP), which includes population from the surrounding area. Rancho Tehama Reserve first appeared as a
census designated place in the
2000 U.S. census. The whole population lived in households. There were 629 households, out of which 150 (23.8%) had children under the age of 18 living in them, 267 (42.4%) were married-couple households, 49 (7.8%) were
cohabiting couple households, 129 (20.5%) had a female householder with no partner present, and 184 (29.3%) had a male householder with no partner present. 182 households (28.9%) were one person, and 95 (15.1%) were one person aged 65 or older. The average household size was 2.5. The age distribution was 316 people (20.1%) under the age of 18, 85 people (5.4%) aged 18 to 24, 376 people (23.9%) aged 25 to 44, 450 people (28.6%) aged 45 to 64, and 345 people (21.9%) who were 65years of age or older. The median age was 45.9years. For every 100 females, there were 110.2 males. == Government ==