PERMFILE124206

• Permit No: C1982056
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 04e-2 AVF Evaluation Fish Creek Mine
• Media Type: D
• Archive: No

sufficient width and depth to clearly exceed the minimum channel sizing criteria noted above.
However, the smaller tributaries [o Fislt Creek were evaluated in terms of these criteria.
Fish Crcek
Fislt Creek is the largest stream in the study area, has the largest valley, and has [Ire greatest
number of identified terraces (See Map I). The source of Fish Creek is in the vicinity of the
Dunckley Flat Tops at an elevation of approximately 10,000 feet. Fish Creek joins Trout Creek
approximately 0.75 miles north of the study area. ,,ta ~„t ~c ~, _ u ; } r ~~, : +~ P ~ ~°1 'S`l ~^~~ ~"'°
High level terraces were identified along Fish Creek. These terraces, designated Tq are froth 25
to 30 feet above the present level of Fish Creek and are composed of a cap of stream alluvium
over bedrock. I{owever, these terraces are isolated from the present valley by slope wash or
bedrock. It should be noted that the Tq terrace areas are isolated and less than 10 acres in size.
Therefore, these high terraces do not meet the geomorphic criteria, as previously specified, and
as such, are not evaluated further in terms of AVF designation.
Within the lower valley of Fish Creek, three terrace levels were mapped. In some places,
additional isolated terrace levels were identified and were included with the mapped terrace level
closest in elevation. The channel and floodplain of Fish Creek were included within the T1
terrace level because of the difficulty of separately depicting this area from a mapping
standpoint.
Available data from test pits and drilling indicate that the valley fill is continuous beneath the
three terrace levels. (Please see Appendix I for a detailed description of the test pit program.)
• The lower part of Fislt Creek, where it narrows beginning in Section 10 TSN,R86W, is Flowing
on or very close to bedrock, although [he alluvial deposits are continuous along [Ire valley
margins.
The T1 terrace is 2 to 5 feet above the channel (as measured from the terrace level to the
observed water surface of Fish Creek in September, 1982), and is from 0 to 100 feet in width.
The terrace is nearly always covered with native range vegetation, except in a few Itay fields
with brotne grass. Native vegetation has been mapped by Camp, Dresser, and McKee (1981)
and is included in sagebrush/cinquefoil community type.
As shown on Map 1, the T2 terrace is 6 to 10 feet above the channel and is from 0 to 800 feet in
width. This terrace is the most extensive in the Fish Creek valley. Native vegetation on this
terrace has also been mapped as the sagebrush/cinquefoil community type altltouglt, two
meadows within thestudy area have been planted to smooth brome.
The Tg terrace is 8 to 12 fee[ above the channel and is from 0 to 400 feet in width. Native
vegetation on this terrace is sagebruch/cinquefoilcommuhity type.
The valley of Fislt Creek narrows for a length of approximately 1600 feet iit Section 2, I I, and
12 TSN,R8G. In [Iris area, the T1 and T2 terraces become narrow and the entire valley is less
than 350 feet in ~vidtlt. The T3 terrace is not found in this area.
Tributaries to Fish Creek
Within the study area, there are two tributaries to Fish Creek which have mappable areas of
alluvium. The southern tributary was examined in the field at several locations, and i[ vvas
I:environ\tracy\docuntent/ExhibTA 3 01/16/98