MushroomRockState Park and RockCity
are, as a duo entry, one of the 8 Wonders of Kansas Geography because...both sites showcase rare Dakota sandstone
concretions, up to 27 feet in diameter, deposited 100 million years ago and
since exposed by the relentless forces of erosion.
Both are found in the Smoky Hill physiographic region of Kansas.
Visitor touches Pulpit Rock. Photo credit KSF
Close up of signatures carved into Pulpit Rock. Photo KSF
The strangely shaped rocks at Mushroom Rock State Park are made of sandstone from the Dakota Formation, deposited along the edge of a Cretaceous
sea about 100 million years ago. Over time, circulating water deposited
a limey cement between the sand grains, creating harder bodies of
sandstone called concretions. Concretions are often spherical. The softer
sandstone of the stem has eroded more rapidly, creating the
mushroom-shaped rock.
This unique geological oddity has drawn
people including Indians, mountain men, soldiers, and present day visitors. Kit Carson was to have said that the area
was his favorite little place.
BECOMING A STATE PARK
Until
1963, the only way to see these spheres was by traveling a rough trail on
privately-owned land. Ellsworth County
constructed a road that year through the heart of the area, allowing access by
automobile. The Ellsworth County
Historical Society secured these 5 acres, owned by two different parties, to be
deeded to the Kansas
Park and Resources
Authority, now Kansas Department of Wildlife and Parks. On April 25, 1965, with over 300 people in
attendance, Mushroom
Rock State
Park was officially presented to the state and
dedicated as a state park. Mushroom Rock
State Park is a satellite park of Kanopolis State Park.
For KDWP Mushroom Rock state park website, click here.
Directions to Mushroom Rock State Park: Two miles
south and two-and-a-half miles west of the intersection of K-140 and K-141.
A few miles south of Minneapolis in Ottawa County is an area covered by
huge sandstone spheres, known as Rock City. About two hundred of these
unusual rocks, some with diameters up to 27 feet, occupy an area
roughly the size of two football fields. They range in diameter from 10-20 feet with the average diameter being 12 feet.
Called concretions by geologists, the spheres weathered out of the sandstone in the Dakota Formation, deposited about 100 million years ago during the Cretaceous Period.
Over time, ground water circulated through the sandy rock and deposited
a calcium carbonate that grew outward in all directions from calcite crystals
or limy fossil fragments scattered throughout the sandstone. As the
softer uncemented portions of the sandy rock weathered away, these
spheres of cemented sandstone remained. The concretions show signs of crossbedding,
angled lines that formed in the sand as it was deposited, probably by
water currents.
Photo courtey Eldon Clark
The site,
owned and operated by a non-profit corporation, has a visitor center and picnic
tables and has been designated as a National Natural Landmark.
Directions to Rock City: 3.6 miles
south of Minneapolis on K-106, then 1/2 mile west on Ivy Road (1051 Ivy Road). Rock City
is operated as a public park from May 1 to September 1 and is open daily 9 a.m.-5 p.m. A small
admission fee is charged. It can be seen all year.
