This EarthCache is located on the
shores of West Lake Okoboji in Lazy Lagoon Park in Triboji Beach.
Parking is close by and the views of the lake from this little park
are lovely.
13,500 years ago, as the glaciers of the last Ice Age retreated,
the Des Moines Lobe left behind it's undeniable footprint on the
landscape of Northwestern Iowa, forming the Iowa Great Lakes.
Geologically, these lakes are a confluence of large glacial
potholes.
The Iowa Great Lakes region was created along the southwest edge
of an ice sheet that surged southward about 13,500 years ago,
halting at what is now the city of Des Moines. This ice stagnated
across the landscape and was followed by several smaller more
subsequent advances over the next 1,500 years. The resulting
topography in the lakes area is especially eye-catching because the
younger glacial advances overlapped the older ice and merged to
create widespread areas of high-relief, hummocky, "knob-and-kettle
terrain." The irregular hills of glacial debris associated with
these compressed ice margins are laced with sloughs, bogs, and
wetland "potholes" which formed as a result of direct contact with
the slowly disintegrating ice.
The Iowa lakes region also served as an important drainage
outlet along the western edge of the melting ice sheet. One
persistent route channeled meltwater southward past the Gull Point
area, through the Okoboji Lake Outlet at its southern end, and into
the Little Sioux River. Extensive sand and gravel deposits along
this route are ample evidence of the huge volumes of water and
sediment discharged by the melting ice.
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The most notable of the Great Lakes is West Lake Okoboji. It is
classified as a "Blue Water Lake". There are only three blue water
lakes in the world: Lake Geneva in Switzerland, Lake Louise in
Alberta, Canada and West Okoboji Lake in Dickenson County,
Iowa.
A blue water lake is a lake in which the water is supplied from
subterranean springs or source of fresh water rather than being
produced by the collection of rainwater and runoff from the
surrounding topology--actions that would produce a lake of murky
and silt-laden water suspending all kinds of detritus.
West Okoboji Lake is the largest of a chain of five connecting
lakes, which is considered part of Iowa's Great Lakes.
According to information obtained from the Iowa Department of
Natural Resources, West Okoboji Lake is comprised of 3,847 surface
acres of water with an average depth of 38 feet and maximum depth
of 136 feet. There are 19.8 miles of shoreline around West Okoboji
Lake and the natural drainage basin is fed by 13,668 acres of land
or approximately 22 square miles. Three State Parks are located
along the shores of West Okoboji Lake, including Pillsbury Point,
Gull Point, and Pike's Point.
West Okoboji Lake was called "Minnetonka" by the Sioux Indians
and translated into "Great Waters". The first settlers decided to
use a version of the name "Okoboozhy" for both lakes known today as
the "Okoboji" lakes.
Most lakes in this region are rounded, flat-bottomed and
shallow, generally less than 20 feet deep. They likely formed as
the glacial ice disintegrated and collapsed. West Okoboji Lake, on
the other hand, is long and narrow in outline with numerous rounded
bays and a maximum depth of approximately 135 feet - the deepest of
Iowa's natural lakes. It is thought to have formed along a
pre-existing lowland which became occupied by an enormous block of
the decaying glacier.
To log this EarthCache, you will need to
perform these tasks:
Please fill a clear glass container with a
clean sample of lake water to examine the following: