About Reliez Valley CDP, California
Reliez Valley is a census-designated place (CDP) in Contra Costa County, California, United States. The population was 2,517 at the 2010 census.
The CDP includes the unincorporated community of Reliez Station and the surrounding area. It is located east of Martinez, north of Pleasant Hill, west of Walnut Creek, and south of Concord.
Reliez Valley is named for the Reliez Creek, which flows through the valley. The creek was named by Spanish soldiers in the early 19th century for the many eucalyptus trees that grew along its banks; the name “Reliez” comes from the Spanish word for “eucalyptus”.