Woodman Hollow State Preserve is located in Webster County, Iowa

Webster County, Iowa

-2010 census:The 2010 census recorded a population of 38,013 in the county, with a population density of . There were 17,035 housing units, of which 15,580 were occupied.-2000 census:...

, 7 miles (11.3 km) miles southeast of Fort Dodge

Fort Dodge, Iowa

Fort Dodge is a city and county seat of Webster County, Iowa, United States, along the Des Moines River. The population was 25,206 in the 2010 census, an increase from 25,136 in the 2000 census. Fort Dodge is a major commercial center for North Central and Northwest Iowa. It is located on U.S...

 and 6 miles (9.7 km) northwest of Lehigh

Lehigh, Iowa

Lehigh is a city in Webster County, Iowa, United States. The population was 497 at the 2000 census.Located in a valley, Lehigh is divided in two by the Des Moines River, unusual for such a small town. Originally the two halves of Lehigh were two separate towns...

. The preserve is a satellite area of Dolliver Memorial State Park

Dolliver Memorial State Park

Dolliver Memorial State Park is a state park of Iowa, USA, featuring high bluffs and deep ravines on the Des Moines River. The park is located south of Fort Dodge and northwest of Lehigh.-Geography:...

, located 2 miles to the south. Some older maps refer to the area as "Woodman's Hollow State Park."

Geological Formation and Early Human Use

Many of the rock bluffs lining the interior of the preserve are composed of sandstones, limestones, and dolostones. The rock was produced over time from chemical and physical processes acting on the bed of ancient marine seaways that once covered vast portions of North America between 65 and 550 million years ago. The shoreline of the ancient seaways migrated back and forth from roughly Oklahoma to Illinois, and the river delta systems deposited clay, mud, peat, and channel sands across the area. Over time, these deposits were compacted and cemented into the familiar rock formations observed today. Significant erosion of glacial deposits by the Des Moines River and associated tributaries has helped to expose these deposits over time after the retreat of the Wisconsin Glaciation about 12,000 to 14,000 years before present. Two man-made rock shelters found within the preserve provided evidence to suggest that Woodland Indians or Archaic Indians inhabited the area as early as 2,800 years before present.

Designation as a State Public Area

The Iowa Board of Conservation purchased the land that would become Woodman Hollow in 1927 from A. S. Woodman. The original intent of the area was for it to be developed as a state park, and in the 1930s the Civilian Conservation Corps constructed an access road, two latrines, some trails, and the foundations for a trail bridge. The State of Iowa later decided to discontinue development of the area and to leave it in its natural condition. The land was officially designated as a biological, geological, and archaeological state preserve on August 12, 1970.

Overview

The preserve features several deep, forested ravines, which combine into a larger ravine with a small creek that empties into the Des Moines River

Des Moines River

The Des Moines River is a tributary river of the Mississippi River, approximately long to its farther headwaters, in the upper Midwestern United States...

. The creek is spring and runoff fed. Sandstone bedrock lines the ravine walls. Several small cascades and waterfalls up to 12 feet (3.7 m) high have carved a shallow gorge through the center of the preserve. The two latrines constructed decades ago were not removed after efforts to develop the area into a state park were abandoned, and have fallen into heavy dis-repair. The access road was removed, and most trails within the park have eroded away or have become overgrown, except for those maintained by the footsteps of infrequent visitors.

Flora

Over 500 species of plants can be found within Woodman Hollow. The preserve is said to have one of the largest varieties of ferns in the state of Iowa. Trees found in the area include white and red oak in the uplands. Numerous old growth trees, some over 300 years in age, exist within the boundaries of the preserve, some old enough to be used in climate reconstruction through Dendrochronology

Dendrochronology

Dendrochronology or tree-ring dating is the scientific method of dating based on the analysis of patterns of tree-rings. Dendrochronology can date the time at which tree rings were formed, in many types of wood, to the exact calendar year...

. Near the river, steep ravine walls on both sides of the creek exceed 100 feet (30.5 m) in height - steep enough to vary the species of flora over short distances.

Access to the Preserve

The entrance to the preserve is on Woodman's Hollow Road, 3 miles (4.8 km) east of Otho

Otho, Iowa

Otho is a city in Webster County, Iowa, United States. The population was 571 at the 2000 census.-Geography:Otho is located at .According to the United States Census Bureau, the city has a total area of , all of it land....

. A small, grassy parking area provides a space for two vehicles. The entrance to the main area of the preserve is a narrow, overgrown corridor between two farm fields that heads south for roughly 1000 feet (304.8 m), which is the old access road grade. The largest of the waterfalls and the beginning of the shallow gorge are directly south of the entrance corridor.

No hunting or camping is allowed within the boundaries of the preserve.