Assertion: lignite | /r/HasProperty | mined for fuel
Facets:
value: by clark
type: OTHER
value: by lewis
type: OTHER
value: by native americans
type: OTHER
value: by american explorers
type: OTHER
Source sentences:
text: Two-thirds of the west of the state are underlain by lignite, which was mined for fuel by Native Americans and by American explorers, Lewis and Clark.