Indian Meadows Proposed Research Natural Area 



CliBatic setting. The net annual precipitation balance for Indian 

 Meadows (from the MAPS database) is -3 inches. This places the 

 site toward the wetter end of the range shown by the sample sites 

 and mid-range among sites similarly classified. Average monthly 

 precipitation for the Lincoln Ranger Station climatic station shows 

 a bimodal distribution, with a primary May maximum and a secondary 

 November peak. (The sample site is at a considerably higher 

 elevation than Lincoln and probably does not reflect the same 

 seasonal distribution of precipitation.) Annual total 

 precipitation for the Lincoln Station shows the 3-year running 

 average exceeding the long-term average most years from the mid- 

 1970s to the mid-1980s, and falling short of the long-term average 

 most years since the mid-1980s. In 1992, the year preceding the 

 DHES sampling, total precipitation fell short of the long-term 

 average by about 4.5 inches. In 1993 total precipitation exceeded 

 the average by about 5 inches. 



Geologic setting. The Indian Meadows area is underlain by glacial 

 deposits of undescribed character. Inferred source areas for till 

 or other glacial deposits include extensive exposures of the Helena 

 Formation, a calcareous component of the Proterozoic-aged Belt 

 series of metasediments . In the immediate area of Indian Meadows, 

 glacial deposits are underlain by Tertiary-aged volcanic, 

 volcaniclastic and sedimentary rocks. Similar volcanic rocks in 

 nearby areas host gold and accessory mineralization, and similar 

 mid-Tertiary sedimentary rocks are described as pyritic in nearby 

 areas. 



Hydrologic type. Indian Meadows occupies a glaciated topographic 

 trough capturing snowmelt, runoff and (probably) local ground water 

 recharged on ridges to the north and south. The Indian Meadows 

 pond sampled at site WET29 has a channelized surface water outlet 

 but lacks channelized inflow. 



Basin characteristics. The Indian Meadows site has catchment to 

 wetland area ratio ranking toward the low end of the range shown 

 by Rocky Mountain sites. Local relief within the small catchment 

 is relatively high. Ground-water flow is probably very local in 

 nature. The water depth of the site is unknown. 



Water chemistry. The WET29 site exhibits dilute, near-neutral 

 calcium bicarbonate chemistry. Equilibrium calculations indicate 

 undersaturation with carbonate minerals. Nitrate and ammonium 

 concentrations were below detection limits, orthophosphorous ranked 

 mid-range among Rocky Mountain sites, and total organic carbon 

 ranked toward the upper end of the range shown by this class of 

 sample sites. 



The Indian Meadows site contains comparatively high concentrations 

 of several trace elements. Concentrations of arsenic, lead, copper 

 and zinc all rank near the top of the ranges shown by Rocky 



