Grant-Kohrs Ranch National Historic Site

Across the US, changes in water availability are altering which plants grow where. These changes are evident at a broad scale. But not all areas experience the same climate in the same way, even within the boundaries of a single national park. A new dataset gives park managers a valuable tool for understanding why vegetation has changed and how it might change in the future under different climate-change scenarios.

In 2007, the Rocky Mountain Inventory and Monitoring Network—a small team of NPS scientists—began monitoring natural resources, called “vital signs,” in Grant-Kohrs Ranch and nearby park units. Vital signs indicate park health and serve as red flags if conditions deteriorate, supporting park managers’ efforts to make science-based management decisions. Learn about the NPS Inventory and Monitoring Division and its work in Grant-Kohrs Ranch National Historic Site.

In May 2025, fire staff from Glacier and Yellowstone national parks assisted Grant-Kohrs Ranch National Historic Site with burning irrigation ditches to ensure that water flows for the 2025 season.

Grant Kohrs Ranch is an outstanding representation of the days of the open range cattle industry in the American West during the 19th and early 20th centuries. Operated by Conrad Warren from 1929-1982, the Grant Kohrs Ranch/Warren Ranch represents the modernization of cattle ranching on the Great Plains of the American West.

Grant-Kohrs Ranch NHS sits adjacent to Deer Lodge, Montana, with just the Clark Fork River corridor--a Superfund site--and a railroad track separating the ranch from the town. The riparian area is choked with thick brush and flashy grass ripe to burn. During dry conditions, trains often ignite fires, potentially posing a threat to both historic structures on the ranch and Deer Lodge. Finally in 2012, NPS fire managers conducted the first prescribed burn.

The Ranch House is contained within the “Home Ranch” building cluster, which was primarily constructed by John Grant and Conrad Kohrs between 1860 and 1919. Closely tied to the establishment of the range cattle ranching industry in Montana and associated with the pioneers of western cattle ranching, the Ranch House and its associated landscape functioned as the nucleus of business transactions and social functions for the once extensive ranching operation.

Across the Intermountain Region, Inventory & Monitoring Division ecologists are helping to track the effects of climate change, provide baseline information for resource management, evaluate new technologies, and inspire the next generation of park stewards. This article highlights accomplishments achieved during fiscal year 2021.

Each park-specific page in the NPS Geodiversity Atlas provides basic information on the significant geologic features and processes occurring in the park. Links to products from Baseline Geologic and Soil Resources Inventories provide access to maps and reports.