The first documented burial was James Slater, on June 11, 1918. The records show his wife and baby were buried here later that year.
On June 3, 1922, Frank C. Jordan, Secretary of The State of California certified the Articles of Incorporation of Pine Mountain Cemetery.
Founder of the Atascadero Colony, Edward G. Lewis was buried in the cemetery in 1950.
Prominent State Senator Chris Jespersen is buried in the cemetery, he earned the first Honorary Degree ever to be granted by Cal Poly. In the 1930's he played an instramental role in saving Cal Poly. Before his death in 1951 he helped to secure funding for the Atascadero State Hospital.