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Topography

the south; but these valleys are usually not very much depressed below the general level. By passing up the Menomonee valley, and across the head branches of the Pishtaka, a canal or rail road may reach the summit by a very gradual and uniform ascent. The valleys of the Menomonee and Bark rivers approach each other at the north, (almost encircling the head waters of the Pishtaka) as if for the purpose of inviting improvements, by canal or rail road, in this direction. Some of the highest points in the western part of the county are probably five hundred feet above Lake Michigan.

The whole county is based upon limestone, mostly of a light bluish-gray color and disposed in thin, nearly horizontal layers or strata. It is an excellent building material, and affords good lime. Some quarries afford a stone full of small cavities, rendering it unfit for polishing, but is used for works of a

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