No copyright indicated for the book except for the section titled "Economic Survey of California and Its Counties" by the California State Chamber of Commerce (pg. 752–1064)
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.
Uploaded a work by California Secretary of State from [https://babel.hathitrust.org/cgi/pt?id=mdp.39015055062312&view=1up&seq=70 California Blue Book 1950, p. p. 64] with UploadWizard