Newmarket was taken over by Kirkland Lake Gold in 2016, and in turn that merged with Agnico Eagle Mines Limited in 2022.

Following the shortfall of the production forecast then mine was sold to Perseverance Gold Corporation who had heap leach oxide gold expertise from their open pit operation at Nagambie.

The company changed management and became focused on establishing sulphide gold resources.

Upon the exhaustion of the open pit sulphide resources, the mine schedule was aimed at transitioning to an underground operation.

Commercial sulphide production from open pits was achieved in 2005 and underground mining commenced in 2006.