EXHIBIT 99.1 TSX: ERO NYSE: ERO June 30, 2021 Ero Copper announces US$110 million streaming agreement with Royal Gold on the NX Gold Mine Vancouver, British Columbia – Ero Copper Corp. (TSX: ERO, NYSE: ERO) ("Ero" or the "Company") is pleased to announce that it has entered into a definitive Precious Metals Purchase Agreement (the "NX Gold Stream") with RGLD Gold AG, a wholly owned subsidiary of Royal Gold Inc. (collectively, "Royal Gold"), in relation to gold production from the NX Gold Mine, located in Ma ...