Sylvan Runkel State Preserve

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State Preserves

Sylvan Runkel State Preserve is a 330-acre preserve containing an outstanding example of Iowa’s Loess Hills landscape, with extensive native prairie covering steep hills. 

The tracts comprising the preserve were acquired by the Iowa Conservation Commission in 1973 and 1980 as part of the 3,000-acre Loess Hills Wildlife Area. In 1985, the Loess Hills Wildlife Area (including the preserve area) became part of a 10,420-acre National Natural Landmark. 

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About the Land

In 1996, the preserve was established for its biological and geological significance, and named in memory of Sylvan Runkel. 

Sylvan Runkel was a forester, naturalist, and educator in many conservation efforts throughout Iowa until his death in 1995. He was a popular field trip leader at the Loess Hills Prairie Seminar, an annual event sponsored by the Western Hills Area Education Agency that draws hundreds of teachers, students, and naturalists to the area now named in his honor. 

The preserve lies along the western edge of the Loess Hills landform region, overlooking the broad Missouri River valley, which was a major route for silt-laden, glacial meltwater flows some 14,000 to 30,000 years ago. 

Thick (up to 150 feet) deposits of silt blown by winds from the floodplain formed what is now the Loess Hills. The crested hills, long narrow summits, branching spurs, and steep slopes of this landscape were later developed by partial erosion of the deep loess deposits. 

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Directions

  1. From Sioux City, drive south on I-29 to Highway 175 (exit 112) at Onawa. 
  2. Turn east (left) on Highway 175 and go 3 miles (through Onawa) to the intersection with County Road L12. 
  3. Turn north (left) and go 7 miles to Nutmeg Avenue. 
  4. Turn east (right), crossing the Little Sioux River, to 178th Street (just across the bridge). 
  5. Turn south (right) and follow this winding road approximately 2 miles to its intersection with Oak Avenue. 
  6. Parking lots are available on the south (right) side of 178th Street on both sides of Oak Avenue. 
  7. A footpath into the preserve is located on the north side of the road just east of the intersection (sign: Sylvan Runkel State Preserve).
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Plants

The preserve supports a variety of prairie, forest, and brush vegetation. A total of over 200 plant species can be found. 

The main feature of the preserve is a prominent ridge with over 100 acres of high-quality native prairie. Extensive communities of dry prairie species occur here. 

In spring, pasqueflower is the first to be found blooming on the prairie, with prairie violet and bastard toadflax soon following. In May, the tiny prairie moonwort fern appears along with prairie dandelion and blue-eyed grass. 

During the summer, blooms include:

  • Butterfly weed
  • Prairie sandreed
  • Downy painted cup
  • Purple coneflower
  • Purple prairie clover
  • Dotted gayfeather Rough blazing star
  • Prairie ragwort  

Several species typical of the Great Plains, including yucca, Lambert’s locoweed, and cut-leaf iron plant, cannot be found in Iowa outside of the Loess Hills. 

By fall, pink gerardia, sky-blue aster, aromatic aster, and showy goldenrod can be found blooming. 

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Birds & Species

Over 100 species of birds have been observed throughout the area. 

Among the woodlands and brushy areas are:

  • Yellow-billed and black-billed cuckoos
  • Whip-poor-will
  • Great crested flycatcher
  • Western kingbird
  • Gray catbird
  • Yellow-throated vireo
  • Yellow warbler
  • Scarlet tanager
  • Indigo bunting
  • Orchard and Baltimore orioles

Twenty-seven species of mammals and fifteen reptiles have been found in the overall wildlife area, including the:

  • Meadow jumping mouse
  • Badger
  • Blue racer
  • Six-lined race­runner
  • Plains spadefoot toad

Of the fifty-six species of butterflies found in the general area, six rare butterflies can be found in this preserve, including the:

  • Dusted skipper
  • Leonard’s skipper
  • Ottoe skipper
  • Regal fritillary
  • Mottled duskywing
  • Hickory hairstreak 
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Visitor Information

The preserve has access points northwest and southeast. 

Hunting is permitted. 

Other natural areas in the Loess Hills include Waubonsie State Park, Turin Loess Hills State Preserve, Loess Hills Wildlife Area, Preparation Canyon State Park, Stone State Park, Mount Talbot State Preserve, Five Ridge Prairie State Preserve, and Loess Hills State Forest.

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