Steptoe Butte Natural Area Preserve

a grassy butte with wildflowers on a sunny day
Steptoe Butte Natural Area Preserve (NAP) was established in 2018 to protect the largest known remaining occurrence of Palouse prairie in Washington. With an estimated 2% of its historic range remaining, the Palouse prairie is considered one of the most endangered ecosystems in the continental United States. The 437-acre preserve was identified by the Washington State Natural Heritage Program for NAP status to protect four rare plants, four priority plant associations, and one rare earthworm species.

Steptoe Butte NAP is a key site in the recovery planning for Spalding’s catchfly (Silene spaldingii), a federally threatened species endemic to Palouse prairie ecosystem, which occurs within the NAP.

Steptoe Butte is the origin of the globally used geologic term “steptoe” meaning an isolated hill or mountain of older rock surrounded by a lava flow. The 3,612-foot quartzite butte was designated by the National Park Service as a National Natural Landmark for its ecological and geological importance.

a photo shows a spalding's catchfly plant in bloom
Spalding's catchfly

Features protected: Four rare plant species: Broadfruit mariposa lily (Calochortus nitidus); Spalding’s catchfly; Small-head goldenweed (Pyrrocoma liatriformis); Scouler’s catchfly (Silene scouleri ssp. scouleri); four priority plant associations: Rough fescue – Idaho fescue – sticky purple geranium grassland (Festuca campestris - Festuca idahoensis - Geranium viscosissimum); (Quaking aspen) / black hawthorn / common cow-parsnip wet shrubland (Populus tremuloides) / Crataegus douglasi / Heracleum maximum); Bluebunch wheatgrass – Idaho fescue Palouse grassland (Pseudoroegneria spicata - Festuca idahoensis); Idaho fescue – common snowberry grassland (Festuca idahoensis - Symphoricarpos albus); and one rare earthworm species, Giant Palouse earthworm (Driloleirus americanus).

Ecoregion: Columbia Plateau

Science, Research and Monitoring

Public and private universities, other research institutions and individual researchers may contact DNR to propose a research project at the site. If you are interested in pursuing research at Steptoe Butte NAP, please contact David Wilderman, natural areas ecologist, at david.wilderman@dnr.wa.gov

Examples of research and monitoring projects

  • Hoskins, E., E.A.R. Welti, and R. Brown. 2024. Lower diversity of forbs in prairie restoration alters pollinator communities but not structural characteristics of plant-pollinator networks. The Journal of the Society for Ecological Restoration, 32(4)
  • Sullivan, A., R. Bunn, and T.E. Cheeke. 2023. Invasion by the annual grass, Ventenata dubia does not impact mycorrhizal fungal abundance in an endangered prairie. The Journal of the Society for Ecological Restoration 31(8)
  • Ellis, J., M. Pope, W. McClelland, and J. Vervoort. 2004. Quartzite buttes in the Palouse region, SE Washington; their relationship to the Belt Basin on the basis of U-Pb LA-ICPMS detrital zircon data. Geological Society of America, 36(4), p.7

Environmental Education and Public Access

Attention: Alerts and Closures

Alert: Steptoe Butte is completely closed for a road improvement project. The anticipated completion is late October 2025. Visit the Washington State Parks Steptoe Butte website for updates on this closure. Steptoe Butte State Park Heritage Site | Washington State Parks

To help conserve the ecology of this preserve, there are no designated access areas within the NAP, unless approved for scientific research and educational purposes. For information on educational opportunities, please contact the DNR Southeast Region Natural Areas Manager.

Washington State Parks and Recreation Commission owns 144 acres adjacent to the DNR property. The State Parks property includes a picnic area and restroom facility at the entrance at the base of the butte, a large viewpoint with interpretive signs at the summit, and the access road connecting the top and bottom, a 1.5-mile portion of which traverses through the DNR-managed NAP. Please visit Washington State Parks Website to find more park information.

Volunteer and Stewardship

Volunteers help with a variety of activities on Natural Areas, including invasive species control, restoration, and monitoring. If you are interested in volunteer and stewardship opportunities at Steptoe Butte NAP, please contact the Southeast Region Natural Areas Manager.

Directions to the Site

From Colfax, head east on WA-26 to US-195 north. After 10 miles turn right onto Scholz Road. Continue right onto Hume Road and in 4 miles turn left onto the Steptoe Butte State Park Road.