What is the {gravity dam} with the {MAX(hydraulic head)} whose {located on terrain feature} is {Columbia River}  ?
What is the dam with the largest hydraulic head located on the earthern features of the Columbia River?
What is the gravity dam with the most hydraulic head whose located on terrain feature is Columbia River?
SELECT ?y WHERE { ?y property:located_on_terrain_feature resource:Columbia_River . ?y rdf:type ontology:gravity_dam . ?y property:hydraulic_head ?z }
select ?ent where {
?ent <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q3497167>.

?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?ent .
?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P4441>.
?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj1.

?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?ent .
?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P706> .
?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q2251> .

}
ORDER BY DESC(?obj1)
LIMIT 5
select ?ent where { ?ent wdt:P31 wd:Q3497167 . ?ent wdt:P4441 ?obj . ?ent wdt:P706 wd:Q2251 } ORDER BY DESC(?obj)LIMIT 5 
Grand Coulee Dam