which had been collected several times between 1899 and 1948 (Branson 1956), but D. brunsoni 

 was not discovered there until almost half a century later. Known localities for the three snail 

 species in the Mission Mountains are within the Mission Mountains Tribal Wilderness of the 

 Confederated Salish and Kootenai Tribes and are relatively secure from human disturbance. None 

 of the snail species has any special federal designation but all three are on the state list of Animal 

 Species of Special Concern maintained by the Montana Natural Heritage Program. 



Live Qreohelix elrodi were reported at the type locality as recently as 1993 (Frest and 

 Johannes 1995). There are no known collections in recent years, however, for O. alpina and 

 Discus brunsoni (Frest and Johannes 1995). Apparently, O. alpina was last collected on 2 August 

 1949 on McDonald Peak, and D. brunsoni was last collected on 29 May 1964 at McDonald Lake 

 (R. B. Branson pers. comm. for both collections). Primary objectives of the study reported here 

 were to 1) revisit the type localities of Qreohelix alpina and Discus brunsoni and, if possible, 

 locate extant populations of each species, and 2) supplement previous brief descriptions of the 

 habitats where each species is found. 

 STUDY SITES AND METHODS 



I used a variety of sources to obtain relatively precise descriptions of type localities and 

 habitat use by Qreohelix alpina and Discus brunsoni , including published literature and 

 conversations with Dr. R. B. Branson, who made the last known collections of each species. The 

 type locality of D. brunsoni was easily identified. Berry (1955) provided a photograph of the site 

 and Branson (1956) added considerable detail of the conditions and physical setting where this 

 species was discovered. The site (Site 1 ) is an extensive talus slope on the north side of 

 McDonald Lake (T19N R19W SI 1) that is accessible by trail. Trips to Site 1 were made on 10 



