Many parts of the Tres Palmeiras exploration belt were mined by Garimpeiros (artisanal miners) using both open pit and underground mining methods from the 1960s to the late 1990s, where average grade of material extracted from numerous small alluvial gold deposits is reported to have been up to 3 oz/t Au (based on anecdotal reports from local garimpeiros). Grab samples from 80 to 200 meter shafts used by the garimpeiros have assayed as high as 475 g/t Au. Widespread gold mineralization was identified in the 1990s by TVX Gold (now part of Kinross) and Battle Mountain Exploration (now part of Newmont). To date, 200 000 meters of core drilling has been completed on the project. Belo Sun took control of the Tres Palmeiras exploration belt in 2003.