Western Pennsylvania’s Buffalo Creek is the largest tributary on the west side of the Allegheny River between Franklin (French Creek) and the Ohio River. From its Butler County headwaters in Fairview Township, it flows 34.4 miles to the Allegheny River at Freeport, Armstrong County. The watershed drains 171 square miles of eastern Butler, western Armstrong, and a small portion of northern Allegheny Counties–including 348.7 miles of streams in the watershed. Buffalo Creek is unique among the major tributaries in this area in that it has maintained relatively good water quality through the rise and decline of industry.
The watershed contains rolling uplands dissected by deeply entrenched valleys. The largest and deepest of these valleys, created by the lower reaches of Buffalo and Little Buffalo Creeks, form gorges with precipitous slopes and sandstone cliffs. The watershed has a total relief of nearly 800 feet, with elevations ranging from approximately 1,525 feet in Sugarcreek Township to 745 feet at Freeport.