The mine was developed in 1963 and closed in 1990, with the resultant job losses leaving the region in economic hardship from which it has never fully recovered. Perched at one of the highest elevation points in the region, the mine stretched over 4,000 acres (16 km²) and had six pits, the largest measuring over 1.6 km (1 mile) in length and the deepest being 183 m (600 ft), placing it below the water table; it is currently half filled with water.
Over 27 years of mining, the pits sustained numerous blasts daily, which some geologists claim have added to natural faults in the rocks. Other geologists and hydrogeologists have claimed that the site is well-situated for hydraulic containment (ie. water flows in, but doesn't leach into surrounding groundwater or surface water systems).
The mine is currently owned by Mario Cortellucci.
Proponents of the landfill plan pointed to its potential for spurring economic development in Kirkland Lake's struggling economy, while opponents pointed to environmental concerns such as the pit's unstable rock walls, which could potentially leach contaminants into the local groundwater supply.
The original landfill proposal considering the Adams Mine for Toronto's garbage can be traced to 1989. The following year, the government of Metro Toronto selected the Adams Mine as the preferred site for replacing the Keele Valley Landfill in Vaughan which was rapidly reaching capacity. In 1995, Metro Toronto began a formal assessment, however the project was rejected on financial and environmental grounds in December of that year.
In 1996, the mine's owner, Notre Development, announced plans to revive the Adams Mine proposal through the private sector. Later the same year, the Progressive Conservative government of Mike Harris made significant changes to the province's Environmental Assessment Act - this resulted in dropping the requirements for a needs assessment and investigation of alternatives to developing a landfill. This gave the provincial government the sole authority to impose time and service limits on environmental assessments.
Investors involved in Notre Development included North Bay businessman Gord McGuinty and Peter Minogue, the husband of Harris' local campaign manager.
Notre Development's 1996 proposal involved a consortium that was known as "Rail Cycle North"; this included the mine's owner, Notre Development, along with waste management companies Canadian Waste Services and Miller Waste Services, and Ontario Northland Railway and CN.
On December 16, 1997, the provincial Ministry of the Environment permitted only a limited Environmental Assessment Board hearing on the site's hydraulic containment system. Heavy opposition was expressed in the hearings, but on June 19, 1998, the EAB approved the project. The opponents filed an appeal with the provincial cabinet, which was subsequently rejected that August. An appeal was then filed for a judicial review. In July 1999, that appeal was rejected by the Divisional Court of Ontario and was similarly rejected by the Ontario Court of Appeal in October of that year.
At the same time, opponents focused on lobbying the recently amalgamated city of Toronto to not accept the Rail Cycle North proposal. On August 3, 2000, Toronto City Council voted to approve the plan to transport the city's waste to Adams Mine. However, due to the volume of community opposition, council reviewed the issue and voted the proposal down that October. Toronto subsequently pursued a proposal to have its garbage shipped to the Carleton Farms Landfill site in Michigan, since the Keele Valley Landfill, as expected, had reached full capacity.
In that fall's municipal elections, Adams Mine supporter Bill Enouy was elected mayor of Kirkland Lake.
In 2001, the Harris government attempted to engineer a campaign of opposition among the Western Ontario communities affected by the Michigan deal, which was seeing hundreds of truckloads of garbage passing on Highway 401 daily; the intent was to force the city of Toronto back into Rail Cycle North's proposal for a landfill using the Adams Mine. The provincial government's campaign included a letter from Michigan Governor John Engler which expressed his state's opposition to accepting Toronto's garbage and explicitly supported the Rail Cycle North proposal, despite the fact that this was perceived as being at odds with Engler's usual positions on waste management. Staffers in Engler's office eventually revealed that the letter had been written at Premier Harris' request.
From 2001 to 2003, Notre Development and the Rail Cycle North consortium continued to pursue avenues to revive the landfill proposal.
In 2003, the Ontario Liberal Party, led by Dalton McGuinty, won the provincial election and on April 5, 2004, provincial Minister of Natural Resources David Ramsay and Minister of the Environment Leona Dombrowsky introduced legislation which revoked all certificates and permits related to the Adams Mine proposal. This had the effect of permanently killing the 1996 plan.
Charlie Angus, a local musician and author, was one of the community leaders who organized the campaign against the Adams Mine proposal. He subsequently ran for political office, and was elected to Parliament in the 2004 federal election.
Toronto continues to export its trash to Michigan, causing a great deal of controversy for southern Ontario and Michigan communities which endure the transport of waste through their communities. Critics continue to point out that Toronto's exporting plan avoids forcing the city and region to come to terms with the waste its citizens generate, however there appears to be little political will to reduce consumption and bring about a regional waste management strategy which will avoid the necessity to export to distant landfills.
The shipping of garbage to Michigan briefly became an issue in the United States presidential election, 2004 when John Kerry, on a campaign stop in Michigan, promised to ban the import of Canadian garbage if he was elected. In September, 2005, the Michigan state legislature voted almost unanimously against accepting Toronto's garbage.Toronto City Council deliberations over the waste site proposal, then-councillors Jack Layton and Olivia Chow surprised their council colleagues by playing The Simpsons episode "Trash of the Titans", in which the comically inept Homer Simpson becomes sanitation commissioner of Springfield and ends up shoving trash from his own and many other communities into a mine, to deleterious effect. "It was absolutely stunning," Layton later told The Globe and Mail. "It was so accurate to what was going on."