Both Redbeard and Golden Gate are at the company's Nullagine project, which produced 72,800 ounces of gold in 2017.
The company is evaluating a significant upgrade of the Nullagine processing plant to support an expansion of its operations.
Redbeard contains 245,700 tonnes at 2.6g/t gold for 20,600oz and the resource covers only 490m of the 2.1km known strike length.
CEO Peter Cash said the resource delivery in record time was an exceptional achievement by the exploration team.
Highlights from drilling at the Golden Gate mining centre intersected high-grade mineralisation below existing openpits, included 11m at 17.6g/t gold within 13m at 15.42g/t from 90m, and showed potential for future underground mining or pit cut-backs.
Cash said Millennium had an aggressive exploration commitment for 2018 with four rigs operating on multiple areas aiming to increase resources and support the expansion studies.
The company is scheduled to start mining this quarter at Nullagine's first ever underground mine after announcing a 22% increase to the Bartons Underground mineral resource earlier this month and a maiden reserve of 270,000 tonnes at 4.5g/t gold for 39,000 ounces.
Millennium shares have traded between A14-34.5c over the past year and last traded at 18.5c intraday, capitalising the company close to A$150 million (US$120 million).