The Walters & Gilardi ranches were established in 1900 when the partners Charles Walters and Joseph Gilardi from Switzerland purchased 1,200 acres of the Hollister-Stowe ranch. Between 1910 to 1915, they bought several large parcels totaling 4,000 acres. They stocked the ranches with beef and dairy cattle, and the tillable portions were cultivated with beans, hay, barley, and alfalfa. They made many improvements to the land, including a concrete irrigation dam and barn foundation which still exist today. However, in response to the outbreak of World War II, between 1938 and 1942 their land was purchased and appropriated to establish Camp San Luis Obispo and provide infantry training ground. Eventually, this land was declared surplus Federal property, and Cal Poly was able to acquire it in 1968 returning it to agriculture and grazing.