The site saw renewed interest in the second half of the 1950s and was subsequently developed by the Jones and Laughlin Steel Corp of Pittsburgh Pennsylvania with first production in 1964.

The closure of the two mines in the Timiskaming District along with the resultant job losses left the region in economic hardship from which it has never fully recovered.

Over 27 years of mining, the pits sustained numerous blasts daily, which some geologists claim have added to natural faults in the rocks.

The claim is that the Government of Ontario failed to pay proper compensation when it passed legislation that revoked the permits that it had previously granted for the site to be operated as a landfill.

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.

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.

At the same time, opponents focused on lobbying the recently amalgamated city of Toronto to not accept the Rail Cycle North proposal.

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.

Charlie Angus, a local musician and author, was one of the community leaders who organized the campaign against the Adams Mine proposal.

During Toronto City Council deliberations over the waste site proposal, then-councillors Jack Layton and Olivia Chow surprised their council colleagues by playing The Simpsons 200th 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.