The producer, which also owns and operates the Island Gold mine in Ontario and the Multatos operation in the Sonora state of Mexico, said the mine's underground crusher and conveyor system are also now in place and have been commissioned.
With the work complete, mining rates are projected to rise to a planned 7,500 tonnes throughput per day by the end of this year.
"This marks a significant milestone for Young-Davidson and turning point for Alamos as we transition from a reinvestment phase to a period of strong free cash flow growth," president and CEO John McCluskey said.
Young-Davidson, an Alamos flagship mine, has a 13-year mineral reserve life and exploration potential, according to the company. It is located 60 kilometres west of Kirkland Lake, near Matachewan.