[3] According to the United States Census Bureau, the CDP has a total area of 15.0 square miles (39 km2), all land.

A post office in Peeples Valley opened circa 1927, and moved to Yarnell Heights in 1929 while retaining its name.

[7] As of the census[9] of 2000, there were 374 people, 176 households, and 127 families residing in the CDP.

There were 230 housing units at an average density of 15.3 per square mile (5.9/km2).

22.7% of all households were made up of individuals, and 11.9% had someone living alone who was 65 years of age or older.