The McKeen Motor Car at the Nevada State Railroad Museum, one of the state's historic treasures, has been designated a national historic landmark by Secretary of the Interior Ken Salazar.Called one of Nevada's significant historic treasures, the McKeen vehicle at the Nevada State Railroad Museum earned the recognition from Salazar and ample praise from Gov. Brian Sandoval.“As we begin to celebrate Nevada's 150th anniversary of statehood in 2014,” said Sandoval, “this is yet another opportunity to attract tourists to our great state.”Approximately 160 such motor cars were built from 1905 to 1920. Nevada's version served on the famed Virginia and …