Linea Divisoria Entre Mexico Y Los Estados Unidos. No. 17.

1901

International Boundary Commission

1:60k

1935 Blackburn’s map of San Diego County, California

1935

Blackburn, O.V.

1:250k

City of San Diego California Water Resources

1937

San Diego (Calif.). Water Department (1901-1963)

1:580k

Yuma County Municipal Airport : Yuma Arizona : Vicinity map

1951

United States. Air Force

1:500k

Geologic Map of California, San Diego - El Centro Sheet.

1962

California Division of Mines and Geology

1:250k

Linea Divisoria Entre Mexico Y Los Estados Unidos. No. 16.

1901

International Boundary Commission

1:60k

Greater San Diego.

1970

Moffett, Jack

Reconnaissance map of the Salton Sink, California

1908

E.M. Douglas

1:500k

Reconnaissance map of the Salton Sink, California

1906

E.M. Douglas; R.B. Marshall; W. Carvel Hall

1:500k

Imperial County California. America's Winter Garden

1934

Imperial County Board of Trade