SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/riverMouth> <http://dbpedia.org/resource/Conowingo_Dam> . ?x <http://dbpedia.org/ontology/source> ?uri . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/River>}
From where does the river start, which flows into the Conowingo dam?
SELECT DISTINCT ?f WHERE { ?g rdf:type ontology:River . ?g property:river_mouth resource:Conowingo_Dam . ?g property:source ?f }
Pennsylvania
The source of the river whose mouth is in Conowingo Dam is [Pennsylvania].
The source of the river flowing into the Konovgo Dam is [Pennsylvania].