Question: Mahanoy Creek is a 51.6 mi tributary of the Susquehanna River, in Northumberland and Schuylkill counties, Pennsylvania, a major river located in the northeastern region of which country?
Sentence (from "Susquehanna River"): With its watershed, it is the 16th-largest river in the United States, and the longest river in the early 21st-century continental United States without commercial boat traffic.
Relevant evidence: No