Question: Westmoreland County, Pennsylvania is located west of a mountain range that runs for about how many miles?
Sentence (from "Westmoreland County, Pennsylvania"): Cut from Lancaster, Northumberland, and later Bedford Counties, Westmoreland County was founded on February 26, 1773 and was the first county in the colony of Pennsylvania in which its entire territorial boundary was located west of the Allegheny Mountains.
Relevant evidence: Yes