The Peterson Drug Company was located in Missoula, Montana, at 216 North Higgins. It was started by Gustave F. Peterson, a Swedish immigrant, who entered into a partnership with his brother, Alexander Peterson, in 1903. By 1918, Alexander Peterson had purchased his brother's interest. For three years, Alexander was the sole proprietor and manager. After 1922, the two brothers owned all the stock and managed the firm together. In 1922, the Petersons had stores at three locations: the Peterson Drug Store at 216 N. Higgins Ave., the Garden City Drug Store at 118 N. Higgins Ave., and Peterson Drug Store No. 3. The store located at 216 N. Higgins remained open when the other branches closed. Several members of the Peterson family were involved in the business, including Gustave, Sr., Gustave F., Jr., and Francis, son of Alexander Peterson. Ownership and management of the Peterson Drug Company later fell to Gustave Peterson, Jr. During the 1940s, ownership passed outside of the Peterson family, although the business kept its name. Harold C. Kohlhase was the company's last owner. By 1980 the business ceased to exist.