Rimfire didn't disclose any information about its new partner, but the farminee has committed to spend up to A$4.5 million over three years, and will take a small equity stake in Rimfire, spending $230,000 buying shares at 3.2c.
GPR needs to spend at least $1.5 million over the next 12 months, with a minimum of $1.2 million going into exploration within a 103sq.km area that includes the 74,300 ounce Sorpresa gold resource, with associated silver, and all of Rimfire's most advanced prospects.
At the end of the 50.1% earn-in period GPR has agreed to fund the development of Sorpresa, with Rimfire to repay its share of the development costs from operating cash flows.
Rimfire will continue to design and control all field work, GPR will be paid $300,000 per annum for corporate costs.
If GPR doesn't meet all earn-in requirements, including funding the development, it gains no interest in the two exploration leases.
Rimfire said would immediately commence logistical planning for geotechnical, metallurgical, hydrological and sterilisation drilling at Sorpresa, and will start the environmental impact study process.
The company has previously envisaged Sorpresa as a potential 10,000ozpa mine by 2022.
Rimfire managing director Craig Riley said GPR shared "a mutual desire to fast track the monetisation of Sorpresa gold discovery whilst, in parallel, embarking on a significant exploration program in the local area for further mineralisation".
Rimfire is now focused on the Northern Area, where the Northern Gold and Transit prospects are considered the most attractive targets, and may be indicative of an intrusion-related gold system.
Recent drilling in the Southern Area found the newly-identified Ordovician-aged rocks were associated with a different phase of volcanism that is not associated with significant large scale deposits such as Cowal and Northparkes.
Rimfire had $225,000 cash at the start of the quarter.
Shares in the minnow were up 50% on the news to hit 6c, its highest level in more than a year, capitalising the company at $9 million.
