Juniata River. The Juniata River is a tributary of the Susquehanna River, approximately 104 miles long, in central Pennsylvania in the United States.
The river is considered scenic along much of its route, having a broad and shallow course passing through several mountain ridges and steeply lined water gaps. It formed an early 18th-century frontier region in Pennsylvania and was the site of French-allied Native American attacks against English colonial settlements during the French and Indian War.
The watershed of the river encompasses an area of approximately 3,400 square miles, approximately one-eighth of the drainage area of the Susquehanna. Approximately two-thirds of the watershed is forested.
It is the second largest tributary of the Susquehanna after the West Branch Susquehanna. The Juniata River forms in western Huntingdon County at the confluence of the Frankstown Branch and the Little Juniata River, between the boroughs of Alexandria and Petersburg.
The river flows southeast through Huntingdon and continues to the small village of Ardenheim, where the Raystown Branch, the longest of the Juniata's tributaries, enters from the southwest. The Juniata continues southeast, through a gap in the Jacks Mountain ridge. On the southeast side of the ridge it receives Aughwick Creek from the south, then flows northeast, along the eastern flank of the Jacks Mountain ridge to Lewistown, where it