Alaska Blue Book (First edition), Alaska Department of Education, Division of State Libraries, p. 5 (published; a comparison with other photos from the period would lead one to believe that it was possibly taken earlier in his term as lieutenant governor)
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.