The inferred resource comprises 23.1 million tonnes at 2 grams per tonne gold.
The deposit starts at surface and remains open in all directions.
It adds to the 4.7Moz resource at Korbel Main, taking Estelle's total resource to 541Mt at 0.4gpt gold for 6.2Moz.
"RPM North is an exceptional new gold discovery within the Estelle Gold district which highlights the massive upside potential of this project," Nova CEO Christopher Gerteisen said.
"This has really changed the future for Nova and our shareholders.
"Nova's management, with much credit to our team on the ground, has taken the Estelle gold project from discovery to a multi-deposit tier one scale 6.2 Moz gold district in a short timeframe and on relatively limited funding."
Gerteisen said there were five drill rigs at Korbel and RPM with more to follow.
They are just two of 15 known gold occurrences at the project.
"I have no doubt we will be drilling and growing our total global resource inventory for many years to come," Gerteisen said.
"We now look forward to a resource upgrade for Korbel Main, incorporating the high-grade feeder zones, in Q4.
"This is a transformational period for Nova. We are truly just getting started at Nova and are excited with what lies ahead for our shareholders."
Nova shares started the month at A12c and rose as high as 19c. The stock last traded 1.6% higher at 15.2c, valuing the company at about $270 million.
