The deal with vendor Wayne Benham is structured with deferred payments over four years, during which Pioneer can exit at any stage with no future liabilities.
Pioneer will take 100% of the project upon payment of $50,000 to Benham, followed by annual payments over four years, totalling $325,000.
An additional $250,000 will be paid upon declaration of a resource estimate of at least five million tons at 1% lithium, or equivalent, within three years from payment of the exercise fee.
That will rise to $500,000 if the resource exceeds 10Mt in the same timeframe.
The Clinton Booth-led Pioneer had A$4.37 million cash on hand at the end of September.
The project covers around 125sq.km immediately south of the boundary between the Winnipeg River and Western Wabigoon sub-provinces of the Superior Craton, straddling a narrow greenstone belt.
It flagged Patriot Lithium's Dryden, Beyond Lithium's Victory and Victory West, and Critical Resources' Mavis Lake projects as being nearby.
Pioneer said fieldwork would benefit from existing infrastructure and proximate location to townships.
Across Ontario and Quebec, Pioneer's portfolio also includes a 90% interest in the Root Lake project, and 100% stakes in the Lauri Lake and LaGrande projects.
The company listed on the ASX on September 28, having completed an oversubscribed initial public offer to raise $5 million at 20c.