Cedar Bluffs State Preserve

Cedar Bluffs is a 223-acre preserve featuring a scenic forested bluffland with sandstone cliffs. It is located ten miles west of Oskaloosa in southwestern Mahaska County. The interesting flora of Cedar Bluffs caught the attention of botanists as early as 1919. It was acquired in 1990 by the Mahaska County Conservation Board with assistance from the Iowa Natural Heritage Foundation, and was dedicated in 1997 as a biological, geological, and archaeological state preserve. 

About the Land

• The preserve is immediately upstream of the confluence of Cedar Creek with the Des Moines River, within the Southern Iowa Drift Plain landform region. The scenic terrain includes 100-foot bluffs of sandstone, box canyons, and small waterfalls. 
• The colorful reddish sandstone outcrops provide one of the best exposures of Cherokee Group sandstones known in southern Iowa. These “channel sandstones” were deposited in ancient river channels that flowed westward across Iowa during the Pennsylvanian period of geologic time, about 300 million years ago. 
• Closer inspection of the rocks reveals intricate cross-bedding, as well as erosional contacts, ripple marks, basal conglomerates, and coalified fossils of plant stems, twigs, leaves, and trees. 
• The sandstone cliffs exhibit huge vertical fractures that have separated large blocks of sandstone from the bluffs in some places.
•  Collapse and breakup of sandstone masses from these fractures have generated large-block talus fields on the lower slopes. Views from the bluff top offer a spectacular vista of the river valley. 
• Iowa’s history is also displayed in cultural resources found here, representing over 8,000 years of use by humans. The Early Archaic through Late Prehistoric sites range from stone tool processing sites to small-size camps to larger habitation sites. 
• A Woodland-period mound is also present. In the mid-1800s, the Des Moines River flowed beneath the bluffs, and was a major steamboat route. The steamboats used to sound their horns while passing the bluffs, which became popularly known as “Echo Rock,” a name that persisted into the early 1900s. 
• In 1849, geologist David Dale Owen traveled up the Des Moines River and referred to the sandstone site as “Raven Cliff.” 

Directions

1. From the intersection of Highway 92 and Highway 163 in Oskaloosa, take Highway 163 south to County Road T39 (Indian Way). 
2. Turn west (right) and follow Indian Way through the town of Beacon. 
3. Continue west on Indian Way and turn south (left) on Galeston Avenue. 
4. After crossing the Des Moines River, turn west (right) onto 290th Street and go 2.5 miles to Elba Avenue. 
5. Go north (right) to a T-intersection with 280th Street. 
6. Go west (left) 2.25 miles to a parking lot on the north side of the road.

Trees & Flora

Over 150 plant species have been found here. The upland woods consist of oak forest with an abundance of creeping fragile fern. The cool, moist, north-facing cliffs and slopes are crowned with a maple-basswood forest with a dense understory of ironwood. Narrow lowlands are characterized by bottomland hardwoods, including silver maple, cottonwood, and hackberry. 

The spring flora is very impressive, with hepatica, bloodroot, Virginia bluebells, and many others. Shallow, acidic soils in the northeastern portion of the preserve have thick coverings of moss. Many ferns are present, including the ubiquitous rattlesnake fern. In addition to vascular plants, twenty-three species of mushrooms have been found at the preserve, including morels and puffballs.   

Wildlife Habitats

Common species of mammals that occur in central Iowa are found at this preserve. The habitat created by the close proximity of Cedar Creek, nearby sandstone bluffs, and mature forest provides habitat for several species of bats. During the winter, bald eagles often roost in protected valleys along the bluffs. 

The preserve is used by William Penn College and Central College. 

Hunting is allowed. Other public areas in the vicinity include Elk Rock State Park and Quercus Wilderness Area.