Complex sentence: It worked the Alaska-Gastineau Mine/Perseverance Mine in the Silver Bow Basin, approximately from Juneau and processed its ore at an old remodeled mill and crushing plant at Sheep Creek.
Split into simpler sentences: It worked the Alaska-Gastineau Mine/Perseverance Mine in the Silver Bow Basin, approximately from Juneau. It processed its ore at an old remodeled mill and crushing plant at Sheep Creek.