Montana Natural Heritage Program forms for plant species of 

 special concern were completed for each site a rare plant was 

 documented ("element occurrence record") , and boundaries mapped 

 on USGS topographic maps. Information from the survey form is 

 presented on the element occurrence printouts (Appendix 5) . 

 ECODATA plots were taken at single sites for three of the species 

 (attached to printouts; Appendix 5) . 



Identifications were made using Vascular Plants of Montana (Dorn 

 1984) and Flora of the Pacific Northwest (Hitchcock and Cronquist 

 1973). More difficult determinations were made using comparison 

 material in either the University of Montana or Montana State 

 University herbaria. Additionally, knowledgeable botanists were 

 also asked to identify some specimens. Voucher specimens are 

 noted in the plant lists at the end of the report (Appendices 6 

 and 7) and deposited at the University of Montana, with duplicate 

 materials at Montana State University. 



Surveys were conducted 18-22 May, 17, 28 and 29 June, 12, 14-16, 

 27-30 July, and 1, 3-14, 17, 26-27 August 1992. There were 

 drought conditions early in the season and it ended early with 

 August snowfall. 



In the following report, "rare plant" will used to refer to 

 vascular plant taxa that are on either the Region 1 - U.S. Forest 

 Service lists of sensitive and watch species, or the Montana 

 Natural Heritage state list of species of concern. The latter 

 list is larger because it includes taxa which are not known or 

 suspected to occur on lands administered by U.S. Forest Service. 



This report should not be viewed as a definitive evaluation but 

 as a preliminary study of rare plant distribution and floristic 

 inventory of the Big Belt and Elkhorn Mountains. Potential 

 habitats for sensitive species are to be addressed in the 

 biological assessment process (Appendix 4) and documented 

 sensitive species sites are to be addressed in biological 

 evaluations (Appendix 5) . 



RESULTS 



OVERVIEW OF PLANTS OF SPECIAL CONCERN 

 WITHIN THE BIG BELT AND ELKHORN MOUNTAINS STUDY AREA 



Ten plant species of state concern have been documented from the 

 Big Belt and Elkhorn Mountains to date, including 17 new records 

 for six of the species as a result of this project. Results are 

 summarized in Table 1 on the following page. All ten of the 

 species occur in the Big Belt Mountains, and the first nine of 

 the ten are known or presumed to be located on land administered 

 by the U.S. Forest Service. Only one of the ten species, Cirsium 

 lonqistylum . is also in the Elkhorn Mountains. A composite map 



