Ponderosa Pines is a census-designated place (CDP) in Gallatin County, Montana, United States. As of the 2020 census, Ponderosa Pines had a population of 665. Formerly a 13,000-acre ranch, the land was subdivided into 10- and 20-acre parcels and sold by a Hawaiian real estate agency starting in 1972. The lots lacked water, sewer, electricity and road access, and some were on such steep terrain that building would be impossible.