Before the Peninsular Railway had built any track or started running interurban operations, F.S. Granger and J.W. Rea, who owned the San Jose Los Gatos Interurban Company, sold their tracks to the Pin to avoid competing with a company backed by the Southern Pacific. The original Pin tracks were from several other already existing interurban companies, such as the Alum Rock Railway Company, the Peninsular Railroad, and the Santa Clara Interurban Railroad. Some of the Peninsular Railroad and Alum Rock Railway trackage in San Jose became owned by the San Jose Railroads and were never a part of the Peninsular Railway. The trackage that the Peninsular Railway built itself was the line to Los Gatos through Campbell, the line along Stevens Creek Road to Cupertino, the two lines along the Mayfield cutoff from Cupertino to Mayfield, and Cupertino to Los Gatos, the spur to Congress Springs from Saratoga, and part of the line to Alum Rock Park. All of the lines were replaced by bus service by the late 1930s.