Map of Area considered in this Report.
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Fig. 1. -- Profile along a line extending due north and south from Baraboo across the north and south ranges. The dotted continuation northward represents the extension of the profile beyond the topographic map, Plate [XXXVII].
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Fig. 2. -- Profile north from Merrimac across the quartzite ranges. The dotted continuation northward represents the extension of the profile beyond the topographic map, Plate [XXXVII].
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I. THE PLAIN SURROUNDING THE QUARTZITE RIDGES.

Topography.—As seen from the top of the quartzite ridges, the surrounding country appears to be an extensive plain, but at closer range it is seen to have considerable relief although there are extensive areas where the surface is nearly flat.

The relief of the surface is of two somewhat different types. In some parts of the area, especially in the western part of the tract shown on Plate [II], the surface is made up of a succession of ridges and valleys. The ridges may be broken by depressions at frequent intervals, but the valleys are nowhere similarly interrupted. It would rarely be possible to walk along a ridge or "divide" for many miles without descending into valleys; but once in a valley in any part of the area, it may be descended without interruption, until the Baraboo, the Wisconsin, the Mississippi, and finally the gulf is reached. In other words, the depressions are continuous, but the elevations are not. This is the first type of topography.