Celtic/Wonder North is a development project, owned and operated by Northern Star Resources Limited (“Northern Star”) and is located in the Northeastern Goldfields of Western Australia, approximately 60 kilometers north of Leonora. Celtic/Wonder North is part of the larger Thunderbox Operations (TBO), approximately 25 kilometers south of the Thunderbox plant. TBO is located within Northern Star’s Yandal Production Center.

Major growth areas at Yandal include establishment of the Wonder underground as a high-grade feed source for the expanded Thunderbox mill. A maiden underground reserve was declared in May 2023, with underground mining expected to commence in the second half of fiscal 2024 (June 30 ending) at Wonder North.