Chillisquaque Creek

Chillisquaque Creek begins at the confluence of East Branch Chillisquaque Creek and Middle Branch Chillisquaque Creek near the northern border of Derry Township, Montour County. It flows west-southwest for a few tenths of a mile before turning south-southwest. After several tenths of a mile, it turns west for a short distance and receives the tributary West Branch Chillisquaque Creek from the right. The creek then turns south-southeast for more than a mile, flowing alongside Pennsylvania Route 54 and crossing it once. In this reach, it briefly flows alongside the western border of Washingtonville before crossing Pennsylvania Route 254 and receiving the tributary Mud Creek from the left. The creek then begins flowing in a roughly west-southwesterly direction and soon enters Liberty Township. It continues flowing in a similar direction in Liberty Township (though it does flow north, west, and then south for several tenths of a mile at one point), flowing through a broad valley with Limestone Ridge on the north and receiving many unnamed tributaries from both sides. After several miles, the creek leaves the valley and crosses Interstate 80. Several tenths of a mile further downstream, it exits Liberty Township and Montour County. Tributaries Chillisquaque Creek has five named direct tributaries: Beaver Run, Mud Creek, West Branch Chillisquaque Creek, East Branch Chillisquaque Creek, and Middle Branch Chillisquaque Creek. Beaver Run joins Chillisquaque Creek upstream of its mouth and its watershed has an area of . Mud Creek joins Chillisquaque Creek upstream of its mouth and its watershed has an area of . West Branch Chillisquaque Creek joins Chillisquaque Creek upstream of its mouth. East Branch Chillisquaque Creek joins Chillisquaque Creek upstream of its mouth, as does Middle Branch Chillisquaque Creek. Their watersheds have areas of and , respectively. ==Hydrology==

Reaches of Chillisquaque Creek are designated as an impaired waterbody. Causes of impairment include sedimentation/siltation and habitat alteration, while likely sources include agriculture and industrial point-source discharge. Many streams in the watershed experience significant impacts due to agriculture, as heavy use of agricultural lands reduces the creek's water quality. A total of of streams, or about 83% of all the stream miles in the watershed, are impaired. The months with the highest average discharge are March, April, and December; their values are , , and , respectively. The PPL power plant contributes about of water to the creek. In the 1970s, the concentration of nitrate as nitrogen in Chillisquaque Creek near Washingtonville ranged from 1.68 to 2.00 milligrams per liter, while the concentration of nitrite as nitrogen ranged from 0.040 to 0.164 milligrams per liter. The concentration of phosphorus ranged from 0.040 to 0.520 milligrams per liter. The organic carbon concentration was 3.0 milligrams per liter in one measurement. The concentration of sulfate ranged from 32.0 to 114 milligrams per liter in the creek's filtered water and the chloride concentration ranged between 8.0 and 14.0 milligrams per liter, again in filtered water. The ammonia concentration ranged from 0.026 to 0.811 milligrams per liter. In the 1970s, the concentration of magnesium in Chillisquaque Creek ranged from 1.50 to 9.50 milligrams per liter in the creek's filtered water and the calcium concentration ranged from 26.4 to 48.8 milligrams per liter, in filtered water. The arsenic concentration was once measured to be 77 micrograms per liter. The cadmium, recoverable chromium, and recoverable copper concentrations were each once measured to be less than 3, less than 20, and 30 micrograms per liter, respectively. The recoverable iron concentration ranged from 160 to 410 micrograms per liter. The concentrations of zinc, lead, manganese, and aluminum were less than 20, less than 50, 50, and 500 micrograms per liter, respectively. Additionally, a detectable amount of nickel was observed in the creek. ==Geography, geology, and climate==

The elevation near the mouth of Chillisquaque Creek is above sea level. The elevation of the creek's source is approximately above sea level. Montour Ridge is located to the south of the watershed. The creek is between wide and has no apparent limestone influence, despite being near Limestone Ridge and flowing through Limestone Township. Oriskany sandstone and Lower Helderberg limestone occur on Limestone Ridge near it. Oriskany cherty sandstone occurs near the confluence of the tributary Mud Creek. Additionally, Black Genesee shales have also been observed near the creek, as does the Tully limestone. Rock of the Hamilton Group is common in the area as well and is in places covered with sandstone boulders of the Pocono Formation. In the early 1900s, the average annual rate of precipitation in the watershed of Chillisquaque Creek was . The creek has relatively warm water. ==Watershed==

The watershed of Chillisquaque Creek has an area of . There are about of streams in the watershed. The land alongside Chillisquaque Creek is mainly used for farming. As of the 1980s, the main crops are corn and soybeans. There is a gauging station on Chillisquaque Creek at Washingtonville. The area of the creek's watershed upstream of this point is . There are two dams in the watershed: the Lake Chillisquaque dam and the Montour Ash Basin No 1 dam. Both were built in 1971. The former drains an area of , while the latter drains an area of . ==History==

Chillisquaque Creek was entered into the Geographic Names Information System on August 2, 1979. Its identifier in the Geographic Names Information System is 1171784. The creek is also known as Chilisquaque Creek. The village was established by 1728 and was known as Chenastry and Otzinachson. Additionally, Andrew Montour historically owned a plantation near the creek's mouth. A Mingo chief named Logan was living at the mouth of the creek in about 1753. An elderly couple were scalped by Indians near the creek in 1782. William Plunket had settled near Chillisquaque Creek as early as 1772. Boyd and Wilson built a mill at the mouth of the creek in 1791. The first Methodist camp meeting in the area was held on the creek from the West Branch Susquehanna River in August 1806. The West Branch Division of the Pennsylvania Canal historically had an aqueduct over the creek. However, by 1842, it was in need of repairs. On July 18 and 19, 1851, a 32-hour-long storm caused Chillisquaque Creek to rise higher than it had in 57 years. Another one, which carries Pennsylvania Route 54, was built in 1930. Another bridge was built in 1946 and carries Pennsylvania Route 254 in Washingtonville. A bridge carrying State Route 4008 was built across the creek in 1957 and was repaired in 2010. A bridge carrying State Route 1004 was built across the creek in 1960. Additionally, two bridges carrying Interstate 80 were built over the creek in 1962 and repaired in the late 1990s. A bridge carrying State Route 4004 over the creek was built in 1987 and another bridge carrying Pennsylvania Route 54 was built in 1992. A bridge carrying State Route 1003 was constructed across the creek in 1993 and a bridge carrying State Route 3003 was built over the creek in 1997. In 2005, another bridge carrying State Route 1004 was built over the creek. A number of bridges have been built over Chillisquaque Creek in Northumberland County as well. One of these was the Rishel Covered Bridge, which was built in 1830 and repaired in 1990. It is listed on the National Register of Historic Places. The Gottlieb Brown Covered Bridge, which carries T594, was built across the creek in 1881 and was repaired in 1985. It is also on the National Register of Historic Places. A bridge carrying State Route 1025 was constructed over the creek in 1926 and a bridge carrying Pennsylvania Route 45 was built over the creek in 1952. A three-span bridge carrying Pennsylvania Route 642 was built over the creek in 1958 and was repaired in 2012. A two-span bridge carrying Pennsylvania Route 405 was built over the creek in 1974. A number of studies and inventories have been carried out on Chillisquaque Creek. Such studies include Pennsylvania's 208 Study in 1979, an assessment by the Pennsylvania Department of Environmental Protection, and an assessment by Bucknell University in 2003. ==Biology==

The drainage basin of Chillisquaque Creek is designated as a Warmwater Fishery and a Migratory Fishery. The creek was observed by A. Joseph Armstrong to lack trout. In 1986, it contained many of the species found in the West Branch Susquehanna River, including rock bass. Smallmouth bass have also been observed in the creek. Disease is moderately common among young-of-the-year smallmouth bass in the creek. 2011 was the first year where diseased smallmouth bass were documented in the creek since studies began in 2009. A tract of forested floodplain known as the Chillisquaque Creek Natural Area (or Bucknell Preserve, Tobias Marsh, or Mexico Road Swamp) is located in Liberty Township, Montour County. In the preserve, there is also a population of cat-tail sedges. Graminoid marshes occur along the creek near Mexico Road. Such marshes are mainly dominated by cattails, grasses, rushes, and sedges. Reaches of Chillisquaque Creek in Derry Township, Montour County would benefit from additional riparian buffering consisting of native trees to mitigate the effects of nonpoint source pollution. A number of bird species occur at the Bucknell Preserve along Chillisquaque Creek. These include marsh wrens and soras. Virginia rails were observed at the site in 1980 and 1984, though it is likely that they still remain there. Additionally, several mussel species that require high levels of water quality to survive have been observed in the creek. In the Montour County reach of the watershed of Chillisquaque Creek, livestock is commonly allowed access to streams. ==Recreation==

At least of Chillisquaque Creek, from Pennsylvania Route 54 at Washingtonville downstream to its mouth, are navigable by canoe. The difficulty rating of the creek is 1 and the scenery is described in Edward Gertler's book Keystone Canoeing as "good". The creek is suitable for beginners and is typically canoeable from March to May, with the exception of dry years. Not much water is required to canoe on it. However, there is no access to the creek's mouth. A greenway corridor for Chillisquaque Creek was proposed in the Montour County Comprehensive Plan. A campsite known as Shangri-La on the Creek is situated on Chillisquaque Creek at the base of Montour Ridge. It has 52 creekside sites and another 115 sites that are forested to varying degrees. Recreational opportunities at the site include fishing and Frisbee golf. A reach of Chillisquaque Creek was once a third-priority candidate for a Pennsylvania Scenic Rivers designation. ==See also==