Mills Creek; Wagner Gulch; Chicago Gulch Mines, Yentna Mining District, Matanuska-Susitna Borough, Alaska, USAi

Regional Level Types
Mills Creek; Wagner Gulch; Chicago Gulch Mines	Group of Mines
Yentna Mining District	Mining District
Matanuska-Susitna Borough	Borough
Alaska	State
USA	Country

Part of a productive placer area of approximately 36 square miles, including streams draining Fairview Mountain, with area of interest generally northeast and southeast of the summit of Fairview Mountain. Some data for Twin Creek and Mills Creek are combined. See also Twin Creek (TL 026) and Pass Creek (TL024). Tributaries to Mills Creek on which gold has been mined are Wagner Gulch and Chicago Gulch.
Location: The best location for this mined area is shown by C.C. Hawley and Associates, Inc. (1978) on Figure 4.2-B(3)) in Sections 8, 9, 16, and 17, T. 26 N., R. 12 W., of the Seward Meridian. Coordinates given are approximately one half mile upstream from Collinsville. The placered area extends approximately two miles upstream into the headwater drainages of Wagner and Chicago Gluches. The locality is also shown by Clark and Cobb (1972, locality 14).
Geology: Mills Creek is part of the productive placer area known as Collinsville or Fairview Mountain which encompasses approximately 36 square miles. Mills Creek drains southeast from the summit of Fairview Mountain over bedrock that is shown by Reed and Nelson (1980) as semi- and unconsolidated Tertiary clastic sediment of the Sterling (?) Formation (Tps) A northeast-striking normal fault cuts the sedimentary strata and parallels the high angle northeast-striking Pass Creek fault mapped to the northwest. No lode occurrences have been found in the placer deposits near Fairview Mountain/Collinsville (Hawley and Clark, 1978). C.C. Hawley and Associates, Inc. (1978) describe placer operations at this locality on auriferous gravels 3 to 10 feet deep, 20 to 30 feet wide. The main gold-bearing section is on top of a brown to orange-brown clay bed about 15 feet deep and consists of about 5 feet of quartz-bearing gravel. The gold is derived from reworking of the Tertiary clastic sediments (Tps) in the Pleistocene. Mills Creek area was mined nearly all the way from confluence with Twin Creek to the headwater gulches of Wagner and Chicago Gulches. C.C. Hawley and Associates, Inc. (1978) report that production from the entire Collinsville area came from about '1.6 million yards of ground mined in a drag line washing plant operation and 100,000 yards mined by sluice box, which respectively, contained about $0.60 and $1/yard gold at $35/ounce.' Grades of 0.78 oz/ton platinum minerals are reported from one area but the exact location is not specified (C.C. Hawley and Associates, Inc., 1978). Some data for Twin Creek and Mills Creek are combined. See also Twin Creek (TL 026) and Pass Creek (TL024). Wagner Gulch and Chicago Gulch, headwater tributaries to Mills Creek, have also been mined.
Workings: C.C.Hawley and Associates, Inc. (1978) described exploratory testing by drill and backhoe and mining with a drag line washing plant and sluice box.
Age: Pleistocene.
Production: Mills Creek area was mined nearly all the way from confluence with Twin Creek to the headwater gulches. C.C.Hawley and Associates, Inc. (1978) report that production from the entire Collinsville area came from about '1.6 million yards of ground mined in a drag line washing plant operation and 100,000 yards mined by sluice box, which respectively contained about $0.60 and $1/yard gold at $35/ounce.' Grades of 0.78 oz/ton platinum minerals are reported from one area but the exact location is not specified (C.C. Hawley and Associates, Inc., 1978).
Reserves: C.C. Hawley and Associates, Inc. (1978) show possible reserve of 640,000 cubic yards in Mills Creek (Fig. 4.2 B(4)) above the confluence with Twin Creek and another 230,000 possible cubic yards possible below the confluence. The probable reserves are largely covered by old tailings.

Commodities (Major) - Au, Pt
Development Status: Yes; small
Deposit Model: Placer Au-PGE (Cox and Singer, 1986; model 39a).

Other Databases

Link to USGS - Alaska:	TL059

Other Regions, Features and Areas containing this locality

References