The listed coordinates will take you to the parking at the trailhead. Continue on down the trail and enjoy the music of the spring water tumbling over layers of geologic history as it joins with the waters of the Upper Iowa. As you enjoy your hike in this pristine area, you may find yourself saying, “I don’t think this is Iowa!” You may say that, but you’ll be wrong; northeast Iowa, untouched by glaciers, has spectacular scenery, often telling its geologic story in the exposed layers of stone that can be seen throughout the Paleozoic Plateau.
In northeast Iowa, cliffs formed of ancient limestone are riddled with sinkholes, caverns, groundwater springs and algific talus slopes (also known as cold-air slopes). The glaciers of the last Ice Age left this region untouched. Because of their unique geology, these hillsides remain cold even on the hottest days and contain plants and animals found during glacial periods 10,000 years ago. Thick layers of mosses, ferns and liverworts can be found on the coldest portions of the slopes, along with yellow and paper birch, mountain maple, yew and balsam fir.
Narrow valleys deeply carved into sedimentary rock of Paleozoic age and a near-absence of glacial deposits define this scenic region, often called “The Driftless Region.” Fossil-bearing strata originated as sediment on tropical sea floors between 300 and 550 million years ago. Rock layers vary in resistance to erosion, producing bluffs, waterfalls, and rapids. Shallow limestone coupled with the dissolving action of groundwater yields numerous caves, springs, and sinkholes. The geology of this region is unique, riddled with algific talus slopes, also known as cold-air slopes. Along this trail overlooking the Upper Iowa River, you will pass towering bluffs of north-facing Galena limestone, as well as rock falls and isolated stone towers. You may feel the rush of cold air from vents in the rock face on a hot summer day, created by the downdraft of air passing through the karst sinkholes, drawn out across ancient ice remaining hidden within.
As you near the end of your hike, you’ll hear the rush of water plummeting over resistant rock from Malanaphy Cave. Malanaphy Cave is the source from which the spring rises, passing around two sides of a boulder near its entrance. Above the spring can be seen more impressive rock walls, but use caution in this area, as the rock is loose and prone to shifting on the steep approach. Further down, closer to its rendezvous with the river, it tumbles ten feet over rock coated with calcareous tufa and moss, known to locals as Malanaphy Falls.
To log this Earthcache, you will need to complete the following tasks.
1) Measure the water temperature near the spring’s source.
Coordinates for this location are:
2)Estimate the elevation change from Malanaphy Cave to the Upper Iowa River. You can take elevation readings near both points and determine the difference. Always use common sense traveling near the stream and riverbanks here.
Coordinates near the confluence are:
3)This is a pristine example of karst topography, with a charming hydrologic feature thrown in. Surely you’ll want photos! Please choose any location of your liking near the cave or along the tumbling stream to take a photo of you and/or your GPSr, uploading it with your “found it” log.
Email the answers to #1 and #2 above to receive credit. Enjoy your visit to this fascinating spot, but please remain on the obvious trails and off the rock walls, so as to maintain the untouched nature of this preserve.
Permission to place this Earthcache has been graciously provided by John Pearson, Botanist/Plant Ecologist with the Iowa Department of Natural Resources.
Iowa Department of Natural Resources Geological Survey
Iowa Underground, Greg A. Brick, Trails Book, 2004