Indeed, Fosterville contributed almost 70% of Canada-domiciled Kirkland Lake's overall gold production for the December quarter, easily eclipsing the output from its Macassa and Holt Complex operations in Canada.
The company also has the Cosmo mine in the Northern Territory and is conducting exploration work there to see if it can be brought back into production. A decision on that could come as early as February.
In the December quarter Fosterville milled 121,998t of ore grading 49.3 grams per tonne gold at a recovery rate of 99.2%.
In the September quarter the mine milled 119,412t, grading 41.8%gpt to produce 158,327oz.
In the prior December quarter the mine processed 98,797t, at 39.7gpt with a 98.6% recovery rate to produce 124,307oz.
Both the December grade of 49.3gpt and the 99.2% recovery rates were records for Fosterville.
The growth in production from both prior periods reflected higher average grades, increased tonnes milled and improved recoveries.
That grade growth comes from the Swan Zone stopes. Production started in those stopes in the third quarter of 2018 and in 2019 the ramp-up in production from the zone led to a 59% grade improvement.
For FY2019 production at Fosterville totalled 619,366oz, a 74% increase from 356,230oz in FY2018. That came from processing 92,874t at an average grade of 39.6gpt and average recoveries of 98.8%.
Mill throughput rates have also contributed to the increase, with an average 1350t per day being processed in the 2019 financial year, in line with expectations. In 2018 the mill was averaging 1250tpd.
At Cosmo, test processing of low grade mineralisation at the Lantern started in early October, leading to 8733oz being produced at the Union Reefs mill during the December quarter.
Proceeds from sales of the NT gold will be put towards capital expenditures pending a decision to resume commercial operations.
Kirkland Lake Gold president and CEO Tony Makuch said both Fosterville and Macassa had excellent years in 2019, with Fosterville easily beating full-year production guidance and Macassa producing more than 240,000oz in line with targets.
He said the company was donating $1 million to support relief and recovery efforts in Australia's eastern states.
"Our operations in Australia have not been affected by the fires but clearly the impact in many areas has been severe and we are pleased to be contributing to the massive relief and recovery effort required in the aftermath of the fires," Makuch said.