St. Joseph (San José) Island, 8 miles east off the coast of Rockport, TX, is a sand barrier island in Aransas County, separated from Matagorda Island on the north by Cedar Bayou and from Mustang Island on the south by Aransas Pass. The St. Joseph Island Ranch, a stretch of land 19 miles long and up to 5 miles wide, was purchased by Richardson in 1936. The ranch became the site Sid chose for a breeding program to develop cattle that would prosper under all range conditions, and the development of an all-purebred Santa Gertrudis herd. In pictures taken during the '40s of the interior of Sid’s island house, one can see the Rocking SJ brand motif in fireplace mantle tiles and andirons, as well as on picture frames. The Rocking SJ brand is still in use today.