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^[[986] 
[[circled]] 2 [[/circled]]

[[attached machine printed pictures and text, upside down:]]
[[pictures of a topographic map key, with captions:]]
Ford

Dam

Dam with lock

Canal lock (point upstream)

U.S. [[township section line?]]

and [[recove?]]

Boundary monument

Bench mark (supplementary bench mark shown by cross and black figures without lettering)

Cemeteries

Church, School (distinguished on recent maps)

[[Col?]]

RELIEF (printed in brown)

Elevation above mean sea level (in black on recent maps)

Contours (Contours showing depth of water printed in blue)

Depression contours

[[?]]

[[printed text, of folded attachment:]]
with a contour interval of 1 to 100 feet, according to the relief of the particular area mapped.
  2. Surveys of areas in which there are problems of average public importance, such as most of the basin of the Mississippi and its tributaries, are made with sufficient detail to be used in the publication of maps on a scale of 1/62,500 (1 inch=nearly 1 mile), with a contour interval of 10 to 100 feet.
  3. Surveys of areas in which the problems are of minor public importance, such as much of the mountain or desert region of Arizona or New Mexico, and the high mountain area of the northwest, are made with sufficient detail to be used in the publication of maps on a scale of 1/125,000 (1 inch=nearly 2 miles) or 1/250,000 (1 inch=nearly 4 miles), with a contour interval of 20 to 250 feet.