Natural Resource Condition Assessments for Grant-Kohrs Ranch National Historic Site

The Natural Resource Condition Assessment (NRCA) Program provides framework, funding, and publishing support to parks to aid in the synthesis and documentation of natural resource conditions. Condition assessment reports are a tool to describe selected park resources, and record a snapshot of their current condition, identify trends, and identify potential or current threats and stressors. Understanding the condition and trend of natural resources is key for parks and NPS planners to appropriately prioritize and allocate stewardship resources.

Grass and shrubs grow along the banks of a small stream flowing through wetlands, with a barn and mountains in the distance.
Riparian Woodland and Clark Fork River

Photo by NPS/M. Surber.

Grant-Kohrs Ranch National Historic Site was established to preserve the site of a once 10 million-acre cattle empire headquarters, and to honor the role of cattlemen in American history. The site is located in western Montana, nestled in the grasslands between mountain ranges. Grant-Kohrs Ranch supports a number of vegetation communities and a variety of plant species. Originally, this area was dominated by native grasses with trees and shrubs along the riparian areas.

Today, the ranch can be divided into three broad vegetation communities: upland grasslands, irrigated pastures and hayfields, and riparian areas. The site is also abundant in wildlife, with at least 35 species of mammals that either pass through seasonally or live on the ranch year-round. A wide variety of bird species also inhabit the ranch at various times of year.

AnchorTraditional NRCA Report: 2015

In an effort to better understand the natural resources and processes present in this park, a Natural Resource Condition Assessment was conducted and written in 2015. National Park Service representatives collaborated with the University of Saint Mary’s – Minnesota to determine park needs and available data. This team chose 13 resource topics to evaluate:

- Grazing

- Uplands (grasslands, non-irrigated)

- Riparian area

- Birds

- Pastures and hayfields

- Periphyton

- Aquatic macroinvertebrates

- Viewscape

- Air quality

- Hydrology

- Water quality

- Soils

- Soundscape

The assessment showed that the natural resources within Grant-Kohrs Ranch had mixed condition statuses. Six resource topics were in good condition (pastures and hayfields, birds, periphyton, aquatic macroinvertebrates, air quality and viewscape); four resource topics were given a status of moderate concern (riparian area, water quality, soundscape and soils); and three resource topics (grazing, uplands and hydrology) were not given a condition rating due to lack of reference or current data. Several threats and stressors influence the condition of multiple resources within Grant-Kohrs Ranch. These include invasive plant species, mining contamination, and the related Superfund remediation activities. The results of this assessment suggest that Grant-Kohrs Ranch National Historic Site is successfully meeting its sustainable ranching and natural resource management goals.

For other reports and natural resource datasets visit the NPS Data Store.

Source: Data Store Collection 7765 (results presented are a subset). To search for additional information, visit the Data Store.

Last updated: August 16, 2022


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