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char~acterlstics known to be sensitive to land management activities ~zeviewed in ~er~shner et al. 2004}, 1n this case, available stream health data including substrate, fish, and n~acr~oinvertebr~ate comixiunities from Two Elk Creek was compared to data fram suitable reference streams. An effort was made to select reference streams that had similar background physical characteristics such as eolo ,stream size, watershed aspect, as well as fish species composition, as much as ~ gy racticable, for comparison taproject-az~ea streams. Given the unigU.e pl~ysiogr~aplaic p characteristics of the Two Elk Creek watershed, Pearl. Creek was the only other zninii~.allyw izxa aired reference stream. which had been surveyed in a similar pl~ysiographic setting. For P com arison of ~ trout o ulations, and to determine whether recent ski area development in the p PP Two Elk water~sl~ed has impacted the stream, trout data collected by W, J.. Miller and Associates 1993 rior~ to the development of Blue Sky Basin were coznpar~ed to data collected by USFS ~ 7P fisheries staff in 2003. St~~~arn .~Iealt~i Arzarysis ~'wo Elk Creek Biological Analysis ~- To evaluate str~eain health for Two Elk Creek, trout abundance data ~nunaber of fisla1100 meters of stream collected in 2003 were compared to 1993 data that were collected before the iin lementation of the Category lZZ project ~i.e. Blue Sky Basin}. A population estimate znade by P W. J. Miller and Associates in 1993 was similar, if not slightly higher, than those made in 2003 b USFS in the same general area. Miller's estimates for brook trout were 32 X95% confidence Y interval of ~ 2 while USFS 2003 population estimates were 27.25 X95% canfidence interval of ~~ . ~ 15,1 ,Sam ling efficiency was low during 2003, resulting in wide confidence intervals. No } p statistically significant difference in population estimates was observed. Several macroinver~ebrate metrics known to be sensitive to the sedimentation of aquatic habitats Black Gore Creek TMDL workgr~oup 2007} were campar~ed between Two Elk Creek and Pearl ~ z ~ Creek. Pearl Creek was similar, although in a smaller drainage area ~~ krri vs. 19 km far Two Elk , to Two Elk Creek. Both streams were found in the same playsiographic setting, and were both classified as Rosgen A-channel types. Pearl Creek is a tributary to Resolutioia Creek, near Camp Hale. Table 4. Macr~oinvertebrate and substrate metrics for reference streams (Pearl Czeek} and Two Elk Creek, The robust stream health class is calculated based on 74% or 1 26% af~reference for metrics that decrease ox increase ~BCI, % fine sediment, respectively, with increasing Impacts. NA =data not available. wRNF Sediment Benthic % Fine Intolerant No. EPT No. Condition No . Sediment Taxa Taxa Ephemeroptera Index Clingezs Pearl Creek 15.6 7 19 '1 5.9 17 Robust Stream Health Threshold < 19.'1 > 5 > 14 > S < 7.4 > 13 Two Elk 2004 12.9. b 17 7 7.2 18 T~~To Elk 2005 I~~A 9 23 6 5.1 22 ~~