Page 6

WISCONSIN BLUE BOOK
forming level-floored valleys with high bordering hills or
bluffs. The drainage is in form tree-like (dendritic), the main
valley being like the trunk of a tree, the small tributary val-
leys like the branches. There are no lakes in the Driftless
Area, and few places requiring artificial drainage to carry off
surface water. In the glaciated area drainage is irregular and
imperfect, leaving many    lakes and marshes; the surface,
while diversified with moraines of several types and showing
the effects of earlier erosion processes, is less hilly because the
deeper valleys have been partly filled by glacial action and
the hills planed down. On the whole, the glaciated area has
a larger per cent of cultivable land than the Driftless, although
in some-sections glacial lakes and marshes are numerous and
extensive. The greatest abundance of lakes is found on the
headwaters of Wisconsin river and along the upper streams
of the St. Croix.
  The mountain land, now the great northern peneplain, to-
gether with considerable areas of the crescentic plain adjoin-
ing it on the south, east, and west, was once heavily timbered,
largely with conifers. This has been the lumbering region,
par excellence, though other parts of the state, both in the
southeast and in the southwest, had plenty of timber for the
uses of the white settlers when they began to arrive. Some
portions of southern Wisconsin, however, were nearly desti-
tute of timber save along the water courses. These were the
"prairies" which seemed so bleak to the pioneer home makers
that for some years they avoided them, preferring the oak
openings for farming purposes. The prairies, however, have
proved exceedingly rich farming lands, and the ease and
quickness with which they could be brought under cultivation
gave the prairie farmers a distinct advantage over those who
settled in the dense woods. It was the prairies and openings
which made Wisconsin so great a producer of wheat in the
pioneer period. Vast deposits of copper and iron ore are
found in the Archean rocks of the northern peneplain, while
the Galena limestone formation in the southwest is the source
of the lead and zinc deposits for which Wisconsin, with ad-
jacent parts of Illinois and Iowa, has long been famous. Lead
mining, indeed, drew the earliest considerable emigration to
Wisconsin, in the years following 1827.