Buffalo Creek is a tributary of the West Branch Susquehanna River in Union County, Pennsylvania, in the United States.

Nonmetals in the water include dissolved oxygen, calcium carbonate, suspended solids, and phosphorus.

Historical industries in the watershed included mills and timbering, but livestock raising and agriculture are more common in the 21st century.

Buffalo Creek then meanders in an eastward direction, passing near a quarry, the community of Kelly Point, and the Lewisburg Federal Penitentiary.

[6] Buffalo Creek joins the West Branch Susquehanna River 7.73 miles (12.44 km) upriver of its mouth.

The concentration rises for the first few miles before declining to under 10 milligrams per liter in the lower reaches of the creek.

[9] The amount of nitrogen flowing through Buffalo Creek and all its tributaries in 2000 and 2008 was approximately 930,000 pounds (420,000 kg) per year.

[10] The pH and calcium carbonate concentration have both increased in the upper reaches of Buffalo Creek since September 2009, as has the water temperature.

[13] Undivided Keyser and Tonoloway Formations occur in the southern and southeastern parts of the Buffalo Creek watershed.

The Bald Eagle Formation occurs in small parts of the western and northwestern areas of the watershed.

The undivided Bloomsburg and Mifflintown Formations occur in a zigzagging band that goes from the northeastern to the southwestern part of the watershed.

The Clinton Group occurs in a zigzagging band immediately north of the Bloomsburg and Mifflinville Formations.

These include the Allenwood-Alvira-Shelmadine, the Dekalb-Ungers-Hazelton, the Edom, the Hagerstown-Elliber-Washington, the Holly-Basher-Monongahela, the Klinesville-Calvin-Meckesville, the Laidig-Buchanan-Meckesville, and the Weikert-Berks-Hartleton soil associations.

[13] There are four different types of soils by levels of permeability and runoff potential in the Buffalo Creek watershed.

[13] Near Mifflinburg, Buffalo Creek is "tiny and twisting" and its path is interrupted by fences and logs.

The prominent Revolutionary War veteran Colonel John Kelly built an estate on the northern bank of Buffalo Creek.

[13][16] A large number of small mills producing grist, cider, woolens, and lumber were once on North Branch Buffalo Creek.

In the early 1900s, the main industries in the creek's watershed included agriculture, furniture factories, flour mills, and brick works.

[11] In modern times the population of the watershed of Buffalo Creek has been rising, unlike the surrounding areas.

[18] Wild trout naturally reproduce in the creek from the headwaters downstream 8th Street bridge in Mifflinburg, a distance of 13.76 miles (22.14 km).

[19] Half of the Pennsylvania Fish and Boat Commission approved trout waters in Union County are in the watershed of Buffalo Creek.

[20] Birds in the Buffalo Creek watershed include raptors, waterfowl, songbirds, and wild turkeys.

Mammals in the watershed include rodents, foxes, raccoons, opossums, skunks, white-tailed deer, and black bears.

[8] In the summer of 2011, the average number of fecal coliform colonies per 100 milliliters of water in the upper reaches of Buffalo Creek ranged from 291 to over 600.

The average number of fecal coliform colonies per 100 milliliters in the lower reaches of the creek ranged from 330 to over 600.

The average number of enterococcus colonies per 100 milliliters in the lower reaches of the creek ranged from 91 to 418.

[21] In the summer of 2011, 4.55% of the bacteroides in the upper part of Buffalo Creek came from humans, 11.13% came from bovines, 34.74% came from pigs, and 49.58% came from other sources, such as horses.

[21] The lower 14.8 miles (23.8 km) of Buffalo Creek, from Mifflinburg downstream to Lewisburg, are navigable by canoe during snowmelt and within four days of hard rain.

The creek's difficulty rating is 1 and its scenery is described as "good" in Edward Gertler's book Keystone Canoeing.

In the watershed, other common recreational activities include driving, cross-country skiing, horseback riding, mountain biking, camping, swimming, and canoeing.