ATAC had announced a maiden 1.68 million ounce inferred resource grading 4.23g/t gold last month for Osiris, part of its Rackla project outside the area under option to gold major Barrick Gold.
Conrad's resource of 1.29Moz contributed the bulk of the overall Osiris resource and the ongoing drilling programme is looking for expansion potential.
"The first three holes confirm that exceptional grades continue along strike at the Middle Zone and identify a predictable, easterly trending zone of near-surface mineralization within and adjacent to the eastern end of the resource open pit," exploration vice president Julia Lane said.
ATAC said it had about C$18 million (US$13.6 million) in its treasury and was spending $7 million ($5.3 million) on exploration at its Osiris and Rau projects.
It was also working with Barrick to advance Orion, where the major can earn 70% by spending $55 million (US$41.6 million) on exploration.
ATAC shares closed unchanged yesterday at C52c, at the lower end of its 52-week range of 45.5-89c.