Question: Fort Peck Dam is located near the county seat of Valley County, Montana, a city with what population in 2015?
Sentence (from "Fort Peck Dam"): At 21026 ft in length and over 250 ft in height, it is the largest hydraulically filled dam in the United States, and creates Fort Peck Lake, the fifth largest man-made lake in the U.S., more than 130 mi long, 200 ft deep, and it has a 1520 mi shoreline which is longer than the state of California's coastline.
Relevant evidence: No