In 1950 the US government sent military advisers to train tribal police along the border of Thailand. Among them was Harold Mason Young, son of American missionaries, who had been born in Burma. Young started helping injured animals, and his collection started getting visitors. The Chiang Mai provincial government set aside 24 acres (9.7 ha) at the base of Suthep Mountain, and the facility was opened to the public in 1957.[1][3]
When Young died in 1974, the property was taken over by Chiang Mai Province. The zoo was expanded to its current 200 acres (81 ha) footprint, transferred to the Zoological Park Organization under the patronage of the King of Thailand, and opened as the official zoo of Chang Mai Province in 1977