The core of the Highland Mountains is formed of Precambrian 

 basement rock in the south and granite of the Boulder Batholith 

 in the north (Alt and Hyndman 1936) . The Humbug Spires are low 

 mountains formed of this granite. A band of calcareous Belt 

 Series sedimentary rock, 5-10 miles wide runs from near the town 

 of Divide west to just east of the Continental Divide (Alt and 

 Hyndman 1986) . The crest of the Highland Mountains are argillite 

 on the north near Red Mountain and quartzite and granite in the 

 south around Table Mountain. Soils at 6,000-7,500 ft throughout 

 most of the north portion of the area are derived from granite 

 and are coarse-textured and well-drained. Soils in the south are 

 derived from metamorphosed sedimentary rocks and are more silty 

 or loamy in texture. Calcareous soils occur sporadically in the 

 Moose Town area and just east of the Continental Divide in the 

 Lime Kiln Hill and head of Fish Creek area (Fig. 1) . Soils near 

 or above timberline are generally shallow and poorly developed. 

 Small cirques along the main divide suggest that the core of the 

 range was glaciated during Pleistocene times. 



Climate of the Highland Mountains is continental-montane 

 with short, cool summers and long, cold winters. Butte, at 5,540 

 ft on the north side of the Highland Mountains, had mean July 

 maximum and mean January minimum of 80.1 and 3 . V'^F respectively 

 from 1950 to 1980 (NOAA 1982) . During this same period mean 

 annual precipitation was 11.7 inches. Divide, at 5,406 ft on the 

 west side of the study area, had mean July maximum and mean 

 January minimum of 79.4 and 8 . 5°F respectively from 1950 to 1980 

 (NOAA 1982) . During this same period mean annual precipitation 

 was 12.4 inches. Precipitation in the Highland Mountains is 

 estimated to vary from 16-30 inches per year based on snow course 

 records (USDA-SCS 1981) . June is the wettest month. 

 Approximately half of the precipitation falls as snow during the 

 winter. 



Vegetation of the Highland Mountains is predominantly 

 coniferous forest dominated by Douglas fir ( Pseudotsuga 

 menziesii ) and lodgepole pine ( Pinus contorta ) . Spruce (Picea 

 engelmannii ) is common along streams and higher cool slopes. 

 Whitebark pine ( Pinus albicaulis ) dominates subalpine and 

 timberline forests. Limber pine (IL. f lexilis ) is locally common 

 on outcrops of calcareous parent material in the Moose Town and 

 Fish Creek areas. Where granite is the parent material, 

 coniferous forest generally dominates on all aspects (narrow 

 mesas above Hells Canyon Creek are an exception) . On soils 

 derived from metasediments, steppe dominated by sagebrush 

 ( Artemisia tridentata ) , rabbit brush ( Chrysothamnus spp.), 

 shrubby cinquefoil ( Potentilla f ruticosa ) and Idaho fescue 

 ( Festuca idahoensis ) , occurs on warm slopes. Meadows dominated 

 by tufted hairgrass ( Deschampsia cespitosa ) and sedges (Carex 

 spp.) are common in Moose Tov/n and Burton Park. Swamp and carr 

 vegetation dominated by bog birch ( Betula glandulosa ) and willov/s 

 ( Salix spp. ) are found along many drainages and in large areas of 



