Fallen Rock State Preserve

Fallen Rock State Preserve is a 122-acre area of scenic forested bluffland with sandstone cliffs. It is located three miles north of Eldora, just south of the town of Steamboat Rock, and immediately west of Tower Rock County Park. It is part of the Iowa River Greenbelt, a band of steep forested land flanking the Iowa River in eastern Hardin County. The Fallen Rock area was purchased in 1974 by the Hardin County Conservation Board and was dedicated as a biological and geological state preserve in 1978. 

Directions

1. From the intersection of Highway 175 and Highway 215 in Eldora, take Highway 175 east 1 mile to County Road S56. 
2. Turn north (left) and drive on this winding road for 4 miles to the south edge of the town of Steamboat Rock (arrow sign: Tower Rock Park). 
3. Turn west (left) into the driveway leading to Steamboat Rock County Park and follow its winding path 0.5 mile to a parking area near the river. 
4. From here, follow the path on foot west about 0.25 mile along the river to the preserve.

Geology

Sandstone outcrops of Pennsylvanian age (300 million years old) and steep bluffs are well represented in this preserve. The Iowa River in this vicinity also separates the younger glacial deposits of the Des Moines Lobe to the west (14,000 years old) from much older glacial deposits on the east (500,000 years old). 

The preserve is almost entirely forested, with some vertical cliff communities and a few small open meadows along the river. Red oak dominates the north-facing forested slopes along the river. Wahoo and leatherwood can be found in the understory. The floodplain supports a mesic bottomland forest community of American elm, black maple, and black walnut. A few mature white pines occur on the sandstone cliffs and rock outcrops. The preserve includes a disjunct stand of paper birch and yellow birch on a talus slope along the river. Large carpets of broom moss and hair-cap moss are also found here. 

Plants

Over 300 plant species have been found in the preserve with an impressive variety of spring wildflowers. Hepatica, rue anemone, Virginia bluebells, wood anemone, and squirrel corn begin the growing season in March and April. By May, many fiddleheads of fern have developed into great colonies among the rock outcrops. Bishop’s cap, downy yellow violet, green dragon, Canada mayflower, false Solomon’s seal, and appendaged waterleaf are among the spring flora. Wild honeysuckle, serviceberry, ninebark, and hawthorn are common shrubs. Summer brings the flowering of starry Solomon’s seal, Jacob’s ladder, and purple joe-pye-weed. Wild four-o’clocks, zigzag goldenrod, blue wood aster, and fall coralroot orchid are the last of the blooming plants for the season. 

Wildlife

The Iowa River is an important flyway for raptors. Broad-winged hawks, red-shouldered hawks, Swainson’s hawks, or bald eagles may be seen during spring or fall migration. A total of sixty-one bird species can be seen at this preserve, including many neotropical migrants (birds that nest in North America and migrate to Central and South America for the winter) such as Cerulean warbler, scarlet tanager, Acadian flycatcher, least flycatcher, and red-eyed vireo. Barred owl, wild turkey, and belted kingfisher are residents here. Cricket frogs and northern leopard frogs can be found along the muddy banks of the Iowa River as well as an occasional beaver or spiny softshell turtle. 

Hunting is allowed. 

See also Hardin City Woodland and Mann Wilderness Area State Preserves. 

Other natural areas along the Iowa River Greenbelt include Hardin City Woodland and Mann Wilderness Area State Preserves, Wildcat Cave, and Pine Lake State Park.