INTRODUCTION 



A sensitive plant species survey was conducted on the Sioux 

 District of Custer National Forest in Carter County, Montana, and 

 Harding County, South Dakota. The primary purpose of this study 

 was to locate and evaluate populations of vascular plant species 

 designated as sensitive by Region 1 of the U.S. Forest Service 

 (USDA 1994) or potentially warranting consideration as sensitive 

 based on information compiled by the respective Natural Heritage 

 Program in Montana and South Dakota (Heidel 1994, Ode 1992). The 

 work also represents a preliminary survey of floristic diversity 

 across the District. Botanical work was conducted concurrently 

 with a sensitive animal species study conducted by the Montana 

 Natural Heritage Program (Hendricks and Reichel 1995a, b; Reichel 

 1995) . 



Surveys to determine the status of rare plant species are being 

 conducted throughout the west in response to the Endangered Species 

 Act of 1973 and to the conservation initiatives of the U.S. Forest 

 Service (USDA Forest Service 1994, Reel et al. 1989) and other 

 agencies. Survey results serve to identify conservation 

 priorities, contribute to conservation strategies, and provide a 

 baseline for sensitive species programs, project reviews and 

 resource management plans at an early stage of development on the 

 Custer National Forest. 



STUDY AREA 



The Sioux District of Custer National Forest spans two counties: 

 Carter County at the extreme southeastern corner of Montana, and 

 Harding County at the extreme northwestern corner of South Dakota 

 (Figure 1) . It is made up of eight separate units spanning a 

 distance of app. 100 miles (161 km) east-to-west. These units were 

 the original lands that made up the Sioux National Forest. The 

 nearest towns are Buffalo and Camp Crook in South Dakota, and 

 Ekalaka in Montana. The Sioux District headguarters of the Custer 

 National Forest is located in Camp Crook. 



The six largest Sioux District units provided the focus of this 

 study: 



Montana Units 

 Chalk Butte 

 Ekalaka Hills 

 Long Pines 



South Dakota Units 

 North Cave Hills 

 South Cave Hills 

 Slim Butte 



Fieldwork did not include the West Short Pines, and was limited in 

 coverage of the East Short Pines; these two smallest South Dakota 

 units are therefore treated only briefly in this report. 



