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o~~ o~ • • SUNNYSIDE GOLD CORPORATION Lake Emma Field Plot Trials Aw~ust,1988 Background to the Lake Emma Site High in the San Juan mountains of southern Colorado, Lake Emma achieved notoriety several years ago when the lake bottom-which had been undermined~ollapsed into the mine workings below. It was fortunate this near-disaster took place on a Sunday, and no lives were lost At the Lake Emma site, about 20 acres have been affected by mining related surface disturbances. One of these disturbances is a large drainage channel which was built after the lake bottom collapsed to divert snowmelt and precipitation runoff away from the glory hole. Material excavated from the construction of the drainage channel, including lake sediments, have been deposited around the lower periphery of the former lake site. Other disturbances include two ore producing open pits being mined above the former lake site. Waste rock from these pits has been stockpiled in various locations. Topsoil has also been salvaged and stockpiled. Surface disturbances from past mining operations long since abandoned are also evident. Ultimately, waste rock, overburden and other materials will be used to backfill the Lake Emma glory hole. Adjacent disturbed azeas will be regraded and revegetated. The reclamation of Lake Emma-and of all other mining disturbances in Colorado since 1976-is governed by the Colorado Mined Land Reclamation Act. Under this Act, a mining operation is required to have an approved permit for all mining and rec] amation activities. These requirements are enforced by the Colorado Division of Mined Land Reclamation and the Mined Land Reclamation Boazd. The Lake Emma site is above timberline at about 12,200 feet in elevation. Characteristic of high elevation sites, it is an azea of high snowfall and a short ,;rowing season. Revegetation at such sites is difficult-a hazsh climate, marginally suitable growth media, and a paucity of adapted plant materials are predictable circumstances. Recognizing the potential difficulty of revegetating mining disturbances at Lake Emma, the Sunnyside Gold Corporation has undertaken a program of revegetadon field plot trials. Twelve plots, covering a total area of 2,500 square feet, were constructed and seeded in late August, 1988, by IMS (Intermountain Soils, Inc). The purpose of these plots is to test revegetation on three growth media using various amendments (or treatments). High Altitude Revegetation Revegetation of high elevation disturbances remains problematic. Problems are exacerbated by harsh climatic conditions, marginal or unsuitable soils, and a :;hors or non-existent supply of seed of adapted plant species. Results in Colorado, Alaska and -1-