Assertion: mining | /r/HasProperty | explored
Facets:
value: extensively
type: DEGREE
Source sentences:
text: Mining took place along a belt that stretched about 100 miles southwest to northeast through Ontonagon, Houghton, and Keweenaw counties.:16–17 Isle Royale, on the north side of Lake Superior, was extensively explored, and a smelter built, but no mining of any importance took place there.