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History:
The word “Isanti” comes
from a division of the Dakotas known as
the Izatys, which may be translated to
mean “Dwell at Knife
Lake”, where
they resided. Click on this link for a
map of this area.
The name “
Rum
River
” is thought to be a mistranslation of the Dakota word Wakan Wakpa meaning
“Spirit River", which flows out of Mde Wakan, “Spirit
Lake”
or Lake Mille Lacs. In
1767 Jonathan Carver stopped at what is now
Peninsula
Point
Two
River
Historical
Park. He is credited with
naming the
Rum
River.
Geology, Soils, and Topography:
Isanti
County
is dominated by glacial deposits. They
include morainic hills, outwash sand plains, glacial lake beds and
numerous marshes, lakes
and streams. Two
kinds of glacial drift of different age and composition have been
deposited in the
County.
The older is the middle
Wisconsin
drift which advanced from the northeast, commonly called the red drift
due to the color of the material which is coarse textured, stony and low
in lime.
The more recent drift was deposited by the Grantsburg sublobe of the Des Moines
lobe as it advanced from the northwest. This
material is grey
when unweathered and is derived mostly from limestone and
calcareous shale. It is less stony
than red drift and is normally fine textured.
Grey
drift is relatively high in lime.
Lake Grantsburg, a lake formed at the same time as the advancement of the latest sublobe, provided the origin for the fertile, silty soils found
along the northern border
of the county.
The Anoka Sand Plain which covers
about 60% of the county was formed by the Mississippi
River
as it retreated from the Grantsburg sublobe.
The sand plain is characterized by
relatively
smooth finger-like depressions, many small isolated marshes, and scattered
dune-like knolls
of
wind-deposited materials. In most
places, the sand overlays grey drift in
thickness of sand
that range from a few
inches to many feet. The
Zimmerman
loamy fine sand and fine sands
are the most common soils developed from these
sandy glacial outwash deposits.
Several belts of morainic hills
formed from material deposited during an early glacial period extend across
the
County. One of the most prominent
is
located in the southwestern corner occurs in Maple
Ridge
Township. This crest of the ridge which is
the highest point in the county is 1,150 feet
above sea level.
Areas of rolling topography also occur in Stanchfield, Springvale, and
Cambridge Townships. In Isanti and North
Branch
Townships
the landscape
is relatively smooth. Topography
is rolling and steep again near the Chisago County line and rises 40 to 70 feet above the lakes and marshes.
The lowest elevation in the county
is 875 feet above sea level at a point where the North Branch of the Sunrise
River
crossed the eastern boundary
of North Branch Township. The maximum elevation change is
275 feet.
Isanti
Co. comprehensive plan 2.0 The Earth page 15.
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