The Glacier Stopped Here. You Should Too!

From Coon Rapids to Des Moines, the Middle Raccoon River forms the southwestern-most edge of the terminal moraine of the Wisconsin glacier, which was present in Iowa until roughly 12,000 years ago. The terminal moraine, where the glacier stopped, forms the split between two major landforms in Iowa: the Des Moines Lobe (recently glaciated) and the Southern Iowa Drift Plain (last glaciated over 500,000 years ago). At Whiterock Conservancy, spend a day hiking the hills of the Southern Iowa Drift Plain on the south side of the river and check out a prairie-covered kame (remnant of the terminal moraine) south of Highway 141.

 

Landscape Features Today

Whiterock Conservancy (WRC)-managed lands are composed of a 4,300-acre contiguous property, straddling two very interesting ecological margins: the Des Moines Lobe/Southern Iowa Drift Plain landform boundary and the upland/riverbottom lands surrounding the Middle Raccoon River. Unique ecological communities are present on the property, from the sand prairies covering Cretaceous Dakota sandstone outcrops and wetland seeps perched on the Middle Raccoon River floodplain to the upland oak-dominated woodlands and ridgetop savannas.

The diversity on the landscape is complemented by another unique aspect of the property: its enormity. Whiterock Conservancy is one of the largest contiguous tracts of land owned by conservation-based organization or agencies in Iowa and serves as the largest land gift in the Midwest to date. Our lands are a treasure and asset to our state, providing ecosystem services as well as space for wildlife habitat, a working farm, and recreational and educational pursuits for Iowa residents and visitors.

Plant Communities

Non-Vascular & Lichen Plant Species List

Vascular Plant Species List

Five predominant plant communities are found at Whiterock: Cool-season Grassland Pasture, Prairie, Oak Forest/Woodland, Oak Savanna and Wetland.

Cool Season Grassland Pasture: Historically, much of the land comprising Whiterock Conservancy was used for row-crop production and intensive cattle grazing. As a result, the native grasslands were replaced by introduced grasses and weedy wildflowers. Much of the landscape today is dominated by smooth brome and other cool season grassland pastures, which we still use for cattle grazing. One of WRC's major projects is the introduction of native grasses, wildflowers and sedges into the cool season grassland pastures in order to provide more diverse grazing season and habitat for grazing and prairie-dependent organisms.

Oak Forest/Woodland: The predominant ecosystem on the property is oak forest, which covers about 1,200 acres of the total landscape. Surveys from the late 1850's tell us that the primary plant communities were once prairie and savanna. However over the last 150 years, the absence of fire has promoted the growth of shrubs and trees and hence much of the historic savannas and prairies have been overwhelmed by woody growth.

The diversity of oaks is great. On the dry ridgetops and hillsides you'll find bur, black and white oaks, while in lower, moister areas, you'll find red and swamp white oak. The oak forests at WRC represent some of the most well-developed forests in west central Iowa and serve as a refuge and stop-over site for many migratory warblers such as the ovenbird, Kentucky warbler, cerulean warbler, veery, wood thrush, yellow-throated vireo, red-eyed vireo, scarlet tanager and Acadian flycatcher.

Prairie: Much like the state of Iowa, the vast majority of the Whiterock landscape was historically covered in tall and mid-grass prairies, but today, very little remains. Currently, a total of 26 acres of native prairie remnants and 600 acres of reconstructed prairie are present on the property, 240-acres of which were recently planted in the fall of 2008, and still more to come.

Prairies here are managed with prescribed fire and mowing invasive species and are currently being integrated into the rotational grazing program. Remnant prairies are generally found at the ends of the ridgetops overlooking the river valley, and harbor unique species of plants such as blue-eyed grass, hoary puccoon, gray-headed coneflower, tuberous Indian plantain, little bluestem, Scribner's panic grass and prairie violet.

Oak Savannas: Oak savannas are a plant community characterized by scattered oak trees with widespread canopies underlain by prairie grasses, sedges and wildflowers that are somewhat shade-tolerant. At the time of European settlement, oak savannas probably covered more than 10% of the state, but succumbed quickly to town-creation, the suppression of fire, overgrazing, farming and logging interests of the growing Iowan population.

Today, the oak savanna ecosystem is one of the most endangered in the region, with less than 0.1% of the original remaining. WRC-managed lands anchor the Raccoon River Savanna Bird Conservation Area, which consists of 54,000 acres of critical bird habitat along the Middle Raccoon River corridor. Today, WRC is actively restoring oak savanna habitat through the mechanical removal of invasive shrubs and trees, and the reintroduction of fire onto the landscape.

Wetland seeps: At Whiterock a unique type of wetland called a wetland seep can be found. Wetland seeps dot the Middle Raccoon River floodplain and are relatively the most "pristine," or in other words, the least damaged plant community on the property.  Although the seeps only comprise about 0.2% of the total landscape, they house a large share of the native and conservative plant flora and provide habitat for many rare invertebrates. The seeps are formed by water flowing by gravity through the porous sandstone hillsides and collecting in the floodplain to create nearly year-round saturated soils where hydric plants thrive. Look for sensitive fern, cinnamon willowherb, indigo bush, greater St. John's wort, turtlehead and many sedges and bulrushes.

Agricultural Disturbance             -Row Crop             -Row Crop Oldfield             -Cut Hay                     -Farm Yard/House	Lowland/Alluvial Forest Upland Conifer Forest
Prairie             -Mid-grass Remnant             -Tallgrass Remnant             -Switchgrass Field             -Tallgrass Field             -Tallgrass Reconstruction	Upland Mixed Forest Upland Oak Forest             -Bur Oak                     -Mixed Oak             -Oak/Hickory             -Red Oak
Cool-season Grassland             -Grass/Hay             -Pasture                      -Dry/Dry-Mesic             -Mesic             -Wet/Wet-Mesic	Upland Woodland/Savanna             -Woodland             -Savanna             -Pseudo-Savanna
Lowland Woodland/Savanna             -Lowland Savanna             -Lowland Woodland	Wetland/Riparian             -Marsh             -Riparian/Aquatic (pond)             -Riparian/River             -Seep

View our photos on Flickr

A diverse wildlife community is the expression of a healthy ecosystem. With 4,300 contiguous acres including prairie, wetland, woodland, oak savanna and riparian zones, the opportunities for Whiterock Conservancy becoming home to habitat sensitive species is remarkable.

Already, wildlife on the Whiterock landscape is abundant. From white-tailed deer to turkey vultures, from bald eagles to great blue herons, and from coyotes to muskrats, the conservancy is teeming with wild creatures.

In particular, we are trying to learn more about our avian species. Since Whiterock Conservancy's managed lands anchor the Raccoon River Savanna Bird Conservation Area, we are taking steps to restore and preserve habitat for many migratory species. One species in particular - the vermillion flycatcher - a rare bird in this area was recently discovered at Whiterock.  We have also partnered with Saving Our Avian Resources (SOAR) to undertake an Osprey Reintroduction Project. 

Otter were stocked at Springbrook State Park a few years ago and now a few of them have migrated up the river to Whiterock. Coyote patrol the valley and their yelping can be heard up and down the valley many evenings. You can see signs of beaver north of the River House on the west side of the river. Squirrels, opossums and rabbits are also common. And, of course, raccoons are our local namesake!