He became engaged in his father's wholesale lumber and shipping business. Knowland was sent by his father in 1888 to Oregon to rebuild the Gardiner Mill. He went to Jackson, Amador County, serving as an envoy of his father. Joseph R. Knowland managed the Kennedy Mining and Milling Company. In the fall of 1891, he left the Sierra to help his ailing father in Alameda. In 1893, he was appointed to a committee to create a panorama of Alameda County for the California Midwinter Exposition of 1894, held in San Francisco.