Assertion: waterfall | /r/CapableOf | retreat approximately 6.8 miles
Facets:
value: southward
type: LOCATION
Source sentences:
text: About 10,900 years ago, the Niagara Falls was between present-day Queenston, Ontario, and Lewiston, New York, but erosion of their crest has caused the waterfalls to retreat approximately 6.8 miles (10.9 km) southward.