2008-03-13_REPORT - C1981019 ‎(2)‎

• Permit No: C1981019
• IBM Index Class Name: REPORT
• Doc Date: 3/13/2008
• Doc Name: 2007 AHR 2007 Revegetation Monitoring Report
• From: Colowyo Coal Company
• To: DRMS
• Annual Report Year: 2007
• Permit Index Doc Type: Hydrology Report
• Email Name: SB1
• Media Type: D
• Archive: No

2.5.5 Target Sage Grouse Reference Area
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The Target Sage Grouse Proposed Reference Area is comprised of approximately 20.5 acres of
gently sloping vegetation (see Plate 5). This reference area is located on a gently sloping ridge
immediately west of Collom Gulch (see Map 2). A total of 31 plant taxai were observed in this reference
area (see Table AB-1). Current annual herbaceous production across the area averaged 514.3 pounds
per acre in 2007 with perennial grasses the dominant category (see Table 1). Ground cover in the
Target Sage Grouse Reference Area (Table 8) consisted of 61.1% live vegetation, 0.1% rock, 28.0%
litter, and bare soil exposure of 10.8%. Perennial cover across the unit i veraged 47.6% with annual and
biennial cover averaging 13.6%. Dominant taxa were snakeweed, Sandberg's bluegrass, cheatgrass, and
western wheatgrass with 13.0%, 9.9%, 9.4%, and 8.5% average cover, respectively. With regard to
diversity, the Target Sage Grouse Reference Area exhibited 3 perennial grasses and 0 perennial fortis
with between 3% and 50% relative cover. '
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This area has been selected as a reference area given empirical data regarding the location of sage
grouse broods during the brooding season. In this regard, CDOW radio-telemetry data from radio-
tagged sage grouse hens showed a significant concentration of observations along this ridge at this
approximate elevation. Similar, but smaller, concentrations were observed along one or two ridges to
the east. However, these may some day be disturbed by Collom mine-related activity and therefore
would not service for long-term reference. Because sage grouse have been consistently documented in
this area during the brooding period, habitat characteristics must necessarily be appropriate for their life-
history requisites. In this regard, use of this area to target the vegetation parameters representative of
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documented sage grouse brood rearing habitat seems appropriate. ~
Rio Tinto Energy America/Colowyo Mine Page 36 Revegetation Monitoring - 2007
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