Creek (Oil) . Arabis fecunda is known only 

 from southwestern Montana. The global 

 distribution for this species is shown on 

 Map 1, p. 3. 



I.5.B.I. Populations currently known extant: 



e. Montana: Information on the newly 



discovered Cattle Gulch population (013) 

 is found on p. 4; the exact location is 

 provided on a map, p. 5. Additional 

 information was gained on the Quartz 

 Hill (005) and Canyon Creek (Oil) sites. 

 Updated occurrence records and maps for 

 these sites are included on pp. 6-8. 

 Information on the other 12 known 

 populations of A. fecunda may be found 

 in Lesica (1985) and Schassberger 

 (1988) . 



I. 6. A. Concise statement of general environment and 



habitat. The Cattle Gulch population occurs 

 in dry, gravelly calcareous soil, on steep 

 southwest-facing slopes, at 6,200 feet in 

 elevation. 



I.e.B.l.b. Regional macroclimate: The long-term weather 

 station nearest to the newly discovered 

 population in the Pioneer Mountains is at 

 Divide, approximately 3.5 miles northeast of 

 the site, at 5,395 ft. in elevation. For the 

 period from 1951-1980, the July mean 

 temperature was 63.3 °F, the January mean was 

 19.1 °F, and the average annual precipitation 

 was 12.39 in. (U.S. Department of Commerce 

 1982) . 



I. 6. B. I.e. Local microclimate. The climate at Cattle 



Gulch is probably similar to that of Divide. 

 However, this site is probably somewhat 

 cooler and may receive more precipitation, as 

 it is 1,000 ft. higher in elevation. 



I.6.B.4. Physiographic and topographic 



characteristics: The Cattle Gulch (013) 

 population occurs on soils derived from the 

 Madison Limestone Formation, comprised of 

 metamorphosed limestone and sandstones, and 

 the Threeforks Formation, comprised of 

 grayish-brown argillaceous limestone 

 (Richards and Pardee 1925) . This A. fecunda 

 population is on steep, southwest-facing 



