CENTENNIAL, Colo. (June 1, 2023) – NioCorp Developments Ltd. (“NioCorp” or the “Company”) (NASDAQ:NB) (TSX:NB) today announced the successful completion of a geotechnical drilling campaign at the Elk Creek Critical Minerals Project (the “Elk Creek Project”) in southeast Nebraska, which was done in advance of the proposed site preparation, grading, heavy construction, and eventual foundation pours …