Question: What is the gravity dam with the most hydraulic head whose located on terrain feature is Columbia River?
Paraphrase: What is the dam with the largest hydraulic head located on the earthern features of the Columbia River?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q3497167 . ?ent wdt:P4441 ?obj . ?ent wdt:P706 wd:Q2251 } ORDER BY DESC(?obj)LIMIT 5 
Answer: Grand Coulee Dam