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?
Context: The Lehigh and Mahanoy Railroad, originally the Quakake Railroad (pronounced quake-ache), was an independently financed railroad planned and built at almost the same time as the Lehigh Valley Railroad (LVRR), when in part, some of its backers were also of the backers (and perhaps officers) of the Lehigh Valley Railroad.  The railroad is mentioned as part of the engineering report following the survey of 1846 by Robert H. Sayre, at the time chief engineer of the Lehigh Coal & Navigation Company, where the branch is "described as part of the overall scheme to connect New York Harbor via the Central Railroad of New Jersey to the frontiers via Lake Erie and the Susquehanna River valley.  The official incorporated name on the report is the Delaware, Lehigh, Schuylkill, & Susquehanna Railroad Co. where the Schuylkill name is the Quakake Creek climb out of the Lehigh Valley and drop down into Delano Junction which has a descent path to Tamaqua, Pennsylvania in the Little Schuylkill River basin.  Accordingly, the Quakake Railroad would become part of the Mahanoy Branch of the Lehigh Valley Railroad in northeastern to north-central Pennsylvania.  The Catawissa region was an important source of iron ores and developed into an Anthracite pig iron smelting center, as did Catasauqua, Pennsylvania also on the line of the Lehigh Valley. Little Mahanoy Creek is a 7.5 mi tributary of Mahanoy Creek in Schuylkill County, Pennsylvania.  It starts in the borough of Frackville and joins Mahanoy Creek in the borough of Gordon.  Its one named tributary is Rattling Run.  The creek's watershed has an area of 11.6 sqmi .  Its watershed is not affected by mining.  Compounds found in the waters of the creek include nitrogen, phosphorus, orthophosphates, phosphates, nitrates, and ammonia. North Mahanoy Creek is a tributary of Mahanoy Creek in Schuylkill County, Pennsylvania, in the United States.  It is approximately 4.4 mi long and flows through Delano Township, Mahanoy Township, and Mahanoy City.  The watershed of the creek has an area of 5.99 sqmi .  The creek is designated as an impaired waterbody due to sedimentation/siltation and water/flow variation from abandoned mine drainage.  The creek is relatively small, an ephemeral stream in its lower reaches, and is located within the Western Middle Anthracite Field. Shenandoah Creek is a tributary of Mahanoy Creek in Schuylkill County, Pennsylvania, in the United States.  It is at least 5 mi long and flows through Shenandoah, West Mahanoy Township, Butler Township, and Girardville. Schwaben Creek is a tributary of Mahanoy Creek in Northumberland County, Pennsylvania, in the United States.  Schwaben Creek is approximately 10.7 mi long.  The creek has two named tributaries, which both join Schwaben Creek fairly close to its mouth.  The tributaries are called Middle Creek and Mouse Creek.  Schwaben Creek flows through Upper Mahanoy Township, Washington Township, and Jackson Township.  Nearly all of the creek's watershed is devoted to agricultural land and forests, although there is some development.  Painted furniture also was made in the Schwaben Creek valley in the 18th and 19th centuries.  The creek is in the ridge-and-valley geographical province. Mahanoy Creek is a 51 mi long tributary of the Susquehanna River in Schuylkill County and Northumberland County, in Pennsylvania, in the United States.  It has eleven officially named tributaries, of which six are direct tributaries and five are sub-tributaries.  These include seven creeks and four runs.  The largest tributary by both length and watershed area is Schwaben Creek, which is 10.7 mi long and drains an area of 30.2 sqmi .  The second-largest by these measures is Zerbe Run, which is 8.3 mi long and drains an area of 13.1 sqmi . The Susquehanna River ( ; Lenape: Siskëwahane) is a major river located in the northeastern United States.  At 464 mi long, it is the longest river on the East Coast of the United States that drains into the Atlantic Ocean, via the Chesapeake Bay.  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. Mahanoy Creek is a 51.6 mi tributary of the Susquehanna River in Northumberland and Schuylkill counties, Pennsylvania.  There are at least 35 sources of acid mine drainage in the creek's watershed.  Anthracite was mined in the upper part of the Mahanoy Creek watershed in the 19th and 20th centuries.  Mahanoy Creek's tributaries include Schwaben Creek, Zerbe Run, Little Mahanoy Creek, Shenandoah Creek, and North Mahanoy Creek.  Little Mahanoy Creek and Schwaben Creek are two streams in the watershed that are unaffected by acid mine drainage.  Schwaben Creek has a higher number and diversity of fish species than the main stem. Little Mahantango Creek is a tributary of Mahantango Creek in Schuylkill County and Northumberland County, in Pennsylvania, in the United States.  It is approximately 9.6 mi long and flows through Eldred Township and Upper Mahantongo Township in Schuylkill County and Upper Mahanoy Township in Northumberland County.  The watershed of the creek has an area of 15.1 sqmi .  The creek has many unnamed tributaries and sub-tributaries; all of them, as well as the main stem, are impaired.  The cause of impairment in Little Mahantango Creek is sedimentation/siltation and the probable source of impairment is agriculture. Mahantango Creek is a 36.2 mi tributary of the Susquehanna River in Dauphin, Northumberland,Schuylkill, and Snyder County counties, Pennsylvania in the United States.
Answer: United States