Assessment of Mines for Importance 



to Bat Species of Concern, Southwestern Montana 



Progress Report: August 18 - November 15, 1997 



INTRODUCTION 



The Bureau of Land Management (BLM) has scheduled the closure of abandoned mines 

 in southwest Montana. Some of these mines may provide habitat critical for hibernation, 

 reproduction, and warm-season roosting for bats, including up to six U.S. Fish and 

 Wildlife Service designated Species of Concern (former category 2 species). Bat Species 

 of Concern that may occur in southwest Montana are Myotis ciliolabrum, M. evotis, M. 

 thysanodes, M. volans, M. yumanensis and Corynorhinus {Plecotus) townsendii. The US 

 Geological Survey (USGS), Biological Resources Division (BRD), has provided funding 

 to the Montana Natural Heritage Program (MTNHP) to conduct a study of abandoned 

 mines in southwest Montana. The study is aimed at identifying mines used by bats and 

 evaluating a variety of external and internal variables that would enhance predictive 

 capabilities for locating active roosts and hibemacula in a broader area. A CIS database 

 of mine locations and surveyed mine openings will be developed. The results of this 

 study will assist in avoiding the elimination of habitat that may be important to bats. 



Field work on this project commenced in late August 1997 corresponding with the 

 signing of a cooperative agreement between USGS and MTNHP. This report 

 smnmarizes field work conducted during August 18 to October 16, 1997. 



METHODS 



Mine sites to be visited for this project were identified from several sources. The Dillon 

 Resource Area (Dillon RA) of the BLM provided a list of 106 mine sites and the 

 Headwaters Resource Area provided an additional six sites. The Ermont, Tidal Wave and 

 Rochester mining districts were identified by the BLM (Dillon RA) as a priority due to 

 the potential for future mine closures in these districts. Additionally, databases 

 developed by the Montana Bureau of Mines and Geology ' (MTBMG) and the state of 

 Montana were queried for abandoned mines in southwest Montana. We focused on 

 visiting mines listed by the BLM and other abandoned mines in the vicinity of those 

 listed. 



Because of the late startup date, our primary objective this field season was to identify 

 abandoned mines on BLM lands having openings suitable for bat entry and external 



The database was developed as pan of an inventory of abandoned and inactive mines on BLM lands in southwest Montana. 

 (Marvin. R K , Metesh, J J . Hargrave, PA., Lonn, J D , Watson, J E , Bowler, T P , and Madison, J P , 1997, Abandoned/Inactive 

 Mines of Montana US Bureau of Land Management, Montana Bureau of Mines and Geology No 348, 513 p ) 



