INTRODUCTION 



The Goat Flat Proposed Research Natural Area is located 

 southwest of Anaconda in the Anaconda Range along the Continental 

 Divide on the Deerlodge National Forest. The area extends from 

 Storm Lake mostly south to Mount Tiny and Goat Flat (Fig. 1) and 

 is centered at about 46°03'N 113°15'W. A portion of the area is 

 within the Anaconda-Pintlar Wilderness. The Goat Flat Proposed 

 Research Natural Area contains 10 special plant species, five of 

 which are Sensitive in Region 1, and a wide variety of upper 

 subalpine and alpine plant communities. 



A preliminary survey of the botanical features of the Goat 

 Flat Proposed Research Natural Area was conducted by the Montana 

 Natural Heritage Program in July and August 1991. 



TOPOGRAPHY AND GEOLOGY 



Altitudes in the Goat Flat Proposed Research Natural Area 

 range from about 8200 ft along the shore of Storm Lake to 9989 ft 

 at the top of Little Rainbow Mountain. Topographically, the area 

 is mountainous and includes gently sloping terrain southeast of 

 Storm Lake, steep mountain slopes rising above the lake basin to 

 a number of peaks, and two small, high-altitude plateaus 

 including Goat Flat and the northeastern portion of the area. 



Storm Lake sits in a glacial cirque surrounded by steep, 

 colluvial slopes. Snow avalanching occurs on several of the 

 colluvial slopes and fans. Much of the glacial moraine in the 

 bottom of the cirque south of the lake appears to have been 

 reworked or overlain by fluvial action. Fluvial fans and aprons 

 occur on the gentler terrain especially southeast of Storm Lake. 

 At high elevations, the landforms are predominantly weathered 

 bedrock and colluvial rubble. Active, frost-patterned, polygonal 

 ground and solifluction terraces occur in portions of Goat Flat 

 itself. 



The bedrock geology of the Goat Flat Proposed Research 

 Natural Area includes both sedimentary and igneous rocks (Calkin 

 and Emmons 1915) . The mountain east of Storm Lake is composed 

 predominantly of medium and basic, granular granodiorite of 

 Tertiary age that is irruptive into the surrounding sedimentary 

 rocks and contains abundant sedimentary inclusions. The area 

 south and west of Storm Lake, including Mount Tiny and Goat Flat, 

 is composed primarily of calcareous shales and impure limestones 

 of Cambrian and Precambrian age. The impure limestones include a 

 great deal of quartz. At higher elevations, some sandstones and 

 quartzitic sandstones occur also. 



