Burnette (1932) and Byram (1932) are unpublished company reports available at the Alaska State Office, BLM, from the minerals department. Jansons and others (1984) described the site as being on Porcupine Creek at an elevation of 1,000 feet in the NW1/4 of section 35 T. 3 N., R. 1 W.. Tysdal (1978 [MF-880-A]) also located the site in section 35, T. 3 N., R. 1 W., of the Seward Meridian. Both authors maps located the site on Porcupine Creek. Martin and others (1915) identified this creek as Porcupine Creek. The 1994 USGS B7 topographic map has labelled this creek Primrose Creek, but the USGS B7-SE topographic calls it Porcupine Creek.
Location: The mine is located on Porcupine Creek at an elevation of 1,000 feet and about 3 miles from trailhead at the Primrose Creek campground (Primrose Landing). It is in the NW1/4 section 35, T. 3 N., R. 1 W., of the Seward Meridian. This is location 81 of Cobb and Tysdal (1980) and location S-214 of Jansons and others (1984). This location is accurate to within a quarter of a mile.
Geology: The bedrock at the mine is the slate and graywacke of the Valdez Group of Late Cretaceous age (Cobb and Tysdal, 1980). The bedrock strikes N17W and dips vertically (Martin and others, 1915). The mineralization consists of quartz-sulfide stringers and veins in a shear zone that strikes N30E and dips nearly vertically (Martin and others, 1915). The veins range from less than 1 inch to 3.2 feet wide and consist of quartz, calcite, arsenopyrite, chalcopyrite, galena, gold, pyrite, stibnite, and sphalerite (Cobb and Tysdal, 1980). Workings at the site reportedly consist of three levels totaling 450 feet (Byram, 1932). Only the adit at the creek level is open. Grab samples from the portal of the upper adit contained 1.572 and 1.166 ounces of gold per ton and 0.6 ounce of silver per ton (Hoekzema and Sherman, 1983). The adit was collapsed when the portal was sampled. Production from the mine consisted of numerous test shipments of 12 to 15 tons that contained a total of 659 ounces of gold and 138 ounces of silver (Hoekzema and Sherman, 1983).
Workings: In 1911, development consisted of surface trenching and a 22-foot-long adit (Martin and others, 1915). In 1912, the Primrose Mining company was formed; it developed two adits and a 75-foot inclined shaft. The mine was sporadically operated from 1913 to 1932. Three levels of workings were developed totaling 450 feet (Byram, 1932). One of three cabins is still standing. There was a mill on the creek below the cabin. A road was constructed from Kenai Lake to the mine; it is currently the Primrose Creek Trail and is still passable by all-terrain vehicles (ATVs). Grab samples from the upper portal assayed 1.572 and 1.166 ounces of gold per ton and 0.6 ounce of silver per ton (Hoekzema and Sherman, 1983). Production from the mine consisted of numerous test shipments of 12 to 15 tons that contained a total of 659 ounces of gold and 138 ounces of silver (Hoekzema and Sherman, 1983). This is recorded production that can be substantiated.
Age: Cretaceous or younger; the veins cut rocks of the Valdez Group of Late Cretaceous age.
Production: Recorded production for the mine was 659 ounces of gold and 138 ounces of silver but reported production was 4,000 ounces of gold by 1931 (Jansons and others, 1984; Burnette, 1932).
Reserves: The U.S. Bureau of Mines estimated a resource of 1,300 tons of ore containing 1.42 ounces of gold per ton and 0.6 ounce of silver per ton (Jansons and others, 1984).

Commodities (Major) - Au; (Minor) - Ag
Development Status: Yes; small
Deposit Model: Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)

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Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.

ⓘ Silver

Mineral List

10 valid minerals.