2012-02-28_REVISION - M1980244 (71)

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February 7, 2007 -3- 063 -2140 2.2 Surface Conditions As illustrated on Drawing 1, the site is composed of mixed pine /spruce forested areas and open grassy areas. Consistent with a historical mining district, there is a considerable amount of disturbed ground. The open areas are likely the result of historical timber harvesting, and there are numerous depressions, test pits, open shafts, and development rock piles which cover significant portions of the site. A large number of dirt access roads traverse the site, many of which are abandoned and overgrown. State highway 67 cuts across the southwest corner of the site. Much of the terrain is moderately to steeply sloped, although flat areas exist in the valley bottom. Soils cover most of the ground, though rock is exposed in several road cuts. 23 Historical Mining Features 2.3.1 Types of Historical Mining Features Several different types of historical mine workings were identified in the Phase I field reconnaissance program. These types include: • Test Pit — A small, shallow excavation generally 3 to 8 feet deep and 5 to 12 feet in diameter. These excavations are generally cone - shaped, but some may be more rectangular if they are in denser soils or bedrock. These features were historically excavated in order to identify /locate potential mineral veins. • Surface Working — A relatively small excavation which is generally larger than a test pit. These features have a shape, size and/or development rock pile large enough to indicate that some rock was actively mined. These features are either cone - shaped depressions larger than approximately 12 feet across or more rectangular shaft -like features less than approximately 25 feet deep. • Open Shaft — A deep vertical opening providing access to a mineral vein and to the associated drifts, stopes, and other underground workings. The opening is usually a rectangle or square 3 to 6 feet wide, but some smaller, less developed shafts have more rounded openings. The larger, more developed shafts usually have log -cabin style cribbed timber supports. There are often old buildings or evidence of narrow gage rail access near major shafts. Open shafts were often associated with significant development rock piles. • Collapsed Shaft — A feature which, based on field observations and/or historical mining records, is likely to have been a shaft (but has caved or collapsed). Smaller depressions adjacent to large waste rock piles with no other obvious source were often classified as collapsed shafts. Remnants of head frames or other buildings, and remnants of the distinctive crib -like timbering seen in many shafts is also evidence of a collapsed shaft. Depressions, smaller rectangular ,e.,,1. 00WHIS,.o s M-0 „E rogrolucrawolotn. s.E,L0,PE80 Golder Associates