The Sacramento TV market didn't include Modesto until the 1500-foot candelabra in Walnut Grove for 3/10/13 went on the air in 1962. Sacramento didn't even have TV at all until 1953 (KCCC-TV 40, which didn't reach Stockton at all) and didn't start getting VHF signals until 1955 (KCRA 3 and KBET 10). Stockton had KOVR 13 starting in 1954, but because its Mount Diablo signal reached the East Bay, none of the big three networks would affiliate with it to avoid competition with their SF signals. KCRA and KBET/KXTV were both at locations in the foothills that reached Sacramento well but didn't get into Modesto at all or very well into Stockton. There was also KTVU on 36 in Stockton, which lasted from 1953 to 1955.
Point being - if you were trying to watch TV in Stockton or especially Modesto before 1962, you were almost certainly pointing a big rooftop antenna at San Francisco.