Rapid Run is a

tributary A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage ...

of Buffalo Creek in

Centre County Centre County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 158,172. Its county seat is Bellefonte. Centre County comprises the State College, PA Metropolitan Statistical Area. History The lands ...

and Union County in

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

, in the United States. It is approximately long and flows through Miles Township in Centre County and Hartley Township, Lewis Township, West Buffalo Township, and Buffalo Township in Union County. The watershed of the stream has an area of . Some streams in the watershed are impacted by nutrients, sediment, ''E. coli'', and thermal radiation and one unnamed tributary is designated as an impaired waterbody. Rapid Run is a freestone mountain stream in the ridge and valley physiographic province. It flows through a lake known as Halfway Lake and also passes through the Rapid Run Gap. Rapid Run is one of the major tributaries of Buffalo Creek. Its watershed is mostly forested, but there is some agricultural land and impervious surfaces as well.

Pennsylvania Route 192 Pennsylvania Route 192 (PA 192) is a state highway located in central Pennsylvania. The western terminus of the route is at PA 144 in Centre Hall. The eastern terminus is at U.S. Route 15 (US 15) in Lewisburg. Route description PA 192 begins at ...

runs alongside the stream for much of its length. A number of bridges have been constructed across the stream. The drainage basin is designated as a High-Quality Coldwater Fishery and a Migratory Fishery. Additionally, a reach of Rapid Run is

Class A Wild Trout Waters Class A Wild Trout Waters are the highest biomass class given to streams in Pennsylvania by the Pennsylvania Fish and Boat Commission. They are considered to contain the highest-quality naturally reproducing trout populations in Pennsylvania. Th ...

. Various eels and freshwater sponges have also been observed in the stream. Rapid Run flows through Bald Eagle State Forest, R.B. Winter State Park, and

Sand Bridge State Park Sand Bridge State Park is a Pennsylvania state park on in Lewis Township, Union County, Pennsylvania in the United States. The park is the smallest state park in Pennsylvania and consists of a picnic area just off Pennsylvania Route 192. It ha ...

Course

Rapid Run looking upstream near its mouth

Rapid Run begins in a valley in Miles Township, Centre County. It flows in a generally east-northeasterly direction for a few miles and receives the tributary Yankee Run from the

left Left may refer to: Music * ''Left'' (Hope of the States album), 2006 * ''Left'' (Monkey House album), 2016 * "Left", a song by Nickelback from the album ''Curb'', 1996 Direction * Left (direction), the relative direction opposite of right * L ...

before entering Hartley Township, Union County. In this township, the stream crosses

and passes by a

spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of water * Spring (mathematics), a geometric surface in the shape of a ...

called

The Little Bubbler ''The'' () is a grammatical article in English, denoting persons or things already mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the m ...

. The stream then turns south-southeast, passing through Halfway Lake, where it receives the tributary Halfway Run from the left. From the southern end of the lake, it continues flowing south-southeast, crossing Pennsylvania Route 192 again and entering a considerably narrower valley that it shares with Route 192. It passes by Bake Oven Mountain and Seven Notch Mountain for several tenths of a mile before turning east-northeast to stay in the valley. After more than a mile, Rapid Run enters Lewis Township, Union County. Here it continues flowing east in its valley, alongside Pennsylvania Route 192 and Jones Mountain. The stream crosses Pennsylvania Route 192 twice and spends several miles in Lewis Township before entering West Buffalo Township. In West Buffalo Township, it continues heading east for more than a mile before crossing Pennsylvania Route 192 one last time and turning east-southeast. The stream then leaves its narrow valley and flows alongside a much shallower, broader one that it shares with Stony Run. After a few miles, it enters Buffalo Township, where it continues flowing southeast. After several tenths of a mile (about 0.5 km), it reaches its confluence with Buffalo Creek. Rapid Run joins Buffalo Creek upstream of its mouth.

Tributaries

Rapid Run has two named tributaries: Yankee Run and Halfway Run. Yankee Run joins Rapid Run upstream of its mouth and its watershed has an area of . Halfway Run joins Rapid Run upstream of its mouth and its watershed has an area of .

Hydrology

A total of of tributaries to Rapid Run are designated as impaired waterbodies. The cause of the impairment is

nutrients A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...

and

siltation Siltation, is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or ...

. The source of the impairment is grazing-related agriculture. The

total maximum daily load A total maximum daily load (TMDL) is a regulatory term in the U.S. Clean Water Act, describing a plan for restoring impaired waters that identifies the maximum amount of a pollutant that a body of water can receive while still meeting water quali ...

date is 2015. In addition to nutrients and sediment, the watershed is impacted by

E. coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...

and thermal radiation. At the point where the stream drains , the average daily

discharge Discharge may refer to Expel or let go * Discharge, the act of firing a gun * Discharge, or termination of employment, the end of an employee's duration with an employer * Military discharge, the release of a member of the armed forces from serv ...

is . Further downstream, where it drains , its average daily discharge is . At the point where it drains , the average daily discharge is . In 2000, the

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...

load in Rapid Run was , while in 2008, it was . This equates to a sediment load of slightly over per year. However, in the future, the load could be reduced by 54.86 percent to per year. In 2000, of sediment came from

streambank In geography, a bank is the land alongside a body of water. Different structures are referred to as ''banks'' in different fields of geography, as follows. In limnology (the study of inland waters), a stream bank or river bank is the terrai ...

erosion, came from

row crop A row crop is a crop that can be planted in rows wide enough to allow it to be tilled or otherwise cultivated by agricultural machinery, machinery tailored for the seasonal activities of row crops. Such crops are sown by drilling or transplanti ...

s, came from low-density urban land, came from

hay Hay is grass, legumes, or other herbaceous plants that have been cut and dried to be stored for use as animal fodder, either for large grazing animals raised as livestock, such as cattle, horses, goats, and sheep, or for smaller domesticated ...

and

pasture Pasture (from the Latin ''pastus'', past participle of ''pascere'', "to feed") is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep, or swine ...

s, and came from

unpaved road Unpaved roads may refer to: * Dirt roads * Gravel roads A gravel road is a type of unpaved road surfaced with gravel that has been brought to the site from a quarry or stream bed. They are common in less-developed nations, and also in the ru ...

s. Other sources contributed of sediment. The

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

loads of Rapid Run in 2000 and 2008 were , respectively. This equates to less than per year. However, the annual load could potentially be reduced by 20.43 percent to . In 2000, of nitrogen came from

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

/subsurface, came from row crops, came from hay and pastures, came from low-density urban land, and came from

septic system Onsite sewage facilities (OSSF), also called septic systems, are wastewater systems designed to treat and dispose of effluent on the same property that produces the wastewater, in areas not served by public sewage infrastructure. A septic tank a ...

s. came from

s, came from

erosion, and came from miscellaneous sources. In 2000, the

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

load in Rapid Run was and in 2008, it was . This equates to less than per year. In the future, the annual load could be reduced by up to 27.91 percent, bringing it down to . In 2000, groundwater/subsurface contributed of phosphorus to the stream, row crops contributed , and hay/pastures contributed . Low-density urban land contributed , septic systems contributed , streambank

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

contributed , and unpaved roads contributed . of phosphorus came from miscellaneous sources. The concentration of

alkalinity Alkalinity (from ar, القلوي, al-qaly, lit=ashes of the saltwort) is the capacity of water to resist acidification. It should not be confused with basicity, which is an absolute measurement on the pH scale. Alkalinity is the strength of ...

in Rapid Run between Buffalo Trail and T-383 is .

Geography, geology, and climate

The elevation near the

mouth In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...

of Rapid Run is above

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...

. The elevation of the stream's

source Source may refer to: Research * Historical document * Historical source * Source (intelligence) or sub source, typically a confidential provider of non open-source intelligence * Source (journalism), a person, publication, publishing institute o ...

is between above sea level. Rapid Run is a mountain stream. A lake known as Halfway Lake is located on Rapid Run. It has an area of and is fed by streams and springs. The lake has a

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

dam. Rapid Run is a

freestone stream In fly fishing, a freestone stream flows seasonally, based on the water supply. In the summer and fall, freestone streams grow warm and have reduced flow because water from snow melt is less readily available. In contrast to limestone streams, which ...

in the

ridge and valley The Ridge-and-Valley Appalachians, also called the Ridge and Valley Province or the Valley and Ridge Appalachians, are a physiographic province of the larger Appalachian division and are also a belt within the Appalachian Mountains extending ...

physiographic province. Upstream of Halfway Lake, Rapid Run flows through a valley known as Brush Valley. Downstream of the lake, it exits this valley through a deep

water gap A water gap is a gap that flowing water has carved through a mountain range or mountain ridge and that still carries water today. Such gaps that no longer carry water currents are called wind gaps. Water gaps and wind gaps often offer a prac ...

. The water gap contains a slope covered in

quartzite Quartzite is a hard, non- foliated metamorphic rock which was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tect ...

boulders, some of which have diameters of more than . Additionally, terrace ridges such as Oven Mountain and Brush Mountain, which have elevations of , are in the watershed. The Rapid Run Gorge is located in the watershed of Rapid Run, just south of Halfway Lake. In the gorge, all five of the rock formations that make up the area's mountains occur: the

Reedsville Formation The Ordovician Reedsville Formation is a mapped surficial bedrock unit in Pennsylvania, Maryland, Virginia, West Virginia, and Tennessee, that extends into the subsurface of Ohio. This rock is a slope-former adjacent to (and stratigraphically be ...

, the

Bald Eagle Formation The Ordovician Bald Eagle Formation is a mapped bedrock unit in central Pennsylvania, USA. It is a ridge-forming unit in the Appalachian Mountains. Description The Bald Eagle is defined as a gray to olive-gray and grayish-red, fine to coarse-gra ...

, the

Juniata Formation The Ordovician Juniata Formation is a mapped bedrock unit in Pennsylvania and Maryland. It is a relative slope-former occurring between the two prominent ridge-forming sandstone units: the Tuscarora Formation and the Bald Eagle Formation in the ...

, the

Tuscarora Formation The Silurian Tuscarora Formation — also known as Tuscarora Sandstone or Tuscarora Quartzite — is a mapped bedrock unit in Pennsylvania, Maryland, West Virginia, and Virginia, USA. Description The Tuscarora is a thin- to thick-bedded fine-gr ...

, and the

Rose Hill Formation The Rose Hill Formation is a geologic formation in West Virginia, United States. This formation dates back to the Silurian period, and is a source of iron ore for nearby foundries A foundry is a factory that produces metal castings. Metals a ...

. In the water gap of Rapid Run, a number of

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

formations are exposed along Pennsylvania Route 192. These

rock formation A rock formation is an isolated, scenic, or spectacular surface rock outcrop. Rock formations are usually the result of weathering and erosion sculpting the existing rock. The term ''rock formation'' can also refer to specific sediment ...

s mainly consist of

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

s, and conglomeratic sandstones that date to the

Ordivician The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. ...

and

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

periods. The strata in the stream's water gap are all inclined to the southeast.

Jökulhlaup A jökulhlaup ( ) (literally "glacial run") is a type of glacial outburst flood. It is an Icelandic term that has been adopted in glaciological terminology in many languages. It originally referred to the well-known subglacial outburst flood ...

surfaces with a length of more than and up to wide occur in the vicinity of Rapid Run. There also used to be an

ice-dammed lake In geology, a proglacial lake is a lake formed either by the damming action of a moraine during the retreat of a melting glacier, a glacial ice dam, or by meltwater trapped against an ice sheet due to isostatic depression of the crust around the ...

near the stream. This ice-dammed lake was the largest in the area, with a volume of . It had an area of and a depth of . The upper reaches of Rapid Run and its tributary Halfway Run were prehistorically the headwaters of Elk Creek, which is now located to the west of R.B. Winter State Park and drains the western part of Brush Valley. However, in the distant past, a right-angle tributary of Rapid Run (which at the time was confined to the Fourteenmile Narrows) cut its way back from near Seven Notch Mountain and "beheaded" the upper reaches of Elk Creek, causing the headwaters of Elk Creek to flow into Rapid Run. The

capture Capture may refer to: *Asteroid capture, a phenomenon in which an asteroid enters a stable orbit around another body *Capture, a software for lighting design, documentation and visualisation *"Capture" a song by Simon Townshend *Capture (band), an ...

of the headwaters of Elk Creek by Rapid Run occurred approximately one million years ago and has been described as a "blatant act of 'stream piracy'".

Aggradation Aggradation (or alluviation) is the term used in geology for the increase in land elevation, typically in a river system, due to the deposition of sediment. Aggradation occurs in areas in which the supply of sediment is greater than the amount o ...

at the mouth of the stream once partly dammed Buffalo Creek, resulting in as much as of fill. A 315-foot segment of Rapid Run contains 27 percent

riffle A riffle is a shallow landform in a flowing channel. Colloquially, it is a shallow place in a river where water flows quickly past rocks. However, in geology a riffle has specific characteristics. Topographic, sedimentary and hydraulic indica ...

s, 33 percent runs, and 40 percent pools. Further downstream, a 340-foot segment of the stream contains 35 percent riffles, 31 percent runs, and 34 percent pools. Still further downstream, a 635-foot segment contains 25 percent riffles, 21 percent runs, and 54 percent pools. The approximate summer mean temperature in Rapid Run is .

Watershed

The

watershed Watershed is a hydrological term, which has been adopted in other fields in a more or less figurative sense. It may refer to: Hydrology * Drainage divide, the line that separates neighbouring drainage basins * Drainage basin, called a "watershe ...

of Rapid Run has an area of . The mouth of the stream is in the

United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

quadrangle of Mifflinburg. However, its source is in the quadrangle of Hartleton. The stream is one of the major tributaries to Buffalo Creek. Its watershed makes up 14 percent of the Buffalo Creek drainage basin. There are a total of of streams in the watershed, of which are on agricultural land. A total of 88 percent of the watershed of Rapid Run is on

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

ed land. Another 7 percent is on

agricultural Agriculture or farming is the practice of cultivating Plant, plants and livestock. Agriculture was the key development in the rise of Sedentism, sedentary human civilization, whereby farming of Domestication, domesticated species created food ...

land and 2 percent is on impervious surfaces. However, the portion of land on impervious surfaces could rise to 7 percent in the future. The only part of the watershed where agricultural land is predominant is the area in the vicinity of the stream's impaired tributary. The

main stem In hydrology, a mainstem (or trunk) is "the primary downstream segment of a river, as contrasted to its tributaries". Water enters the mainstem from the river's drainage basin, the land area through which the mainstem and its tributaries flow.. A ...

and all of its other tributaries are on forested land. There are of

no-till No-till farming (also known as zero tillage or direct drilling) is an agricultural technique for growing crops or pasture without disturbing the soil through tillage. No-till farming decreases the amount of soil erosion tillage causes in certai ...

conversions in the watershed. The agricultural land in the watershed of Rapid Run includes of row crops and of hay and pastures. A total of of agricultural land is on slopes of more than 3 percent. The watershed contains of unpaved roads. The headwaters of the stream are in a

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

y area. Pennsylvania Route 192 runs alongside Rapid run for much of its length. For this reason, access to the stream is easy.

History

Rapid Run was entered into the

Geographic Names Information System The Geographic Names Information System (GNIS) is a database of name and locative information about more than two million physical and cultural features throughout the United States and its territories, Antarctica, and the associated states of ...

on August 2, 1979. Its identifier in the Geographic Names Information System is 1193170. The stream is also known as Yankee Run. This name appears in ''Place Names of Centre County Pennsylvania: A Geographical Analysis'', which was published in 1969. Daniel Reish of

Berks County, Pennsylvania Berks County ( Pennsylvania German: ''Barricks Kaundi'') is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 428,849. The county seat is Reading. The Schuylkill River, a tributary of the Delaware Ri ...

settled in the vicinity of Rapid Run in Forest Hill in 1820 and constructed a

sawmill A sawmill (saw mill, saw-mill) or lumber mill is a facility where logs are cut into lumber. Modern sawmills use a motorized saw to cut logs lengthwise to make long pieces, and crosswise to length depending on standard or custom sizes (dimensi ...

gristmill A gristmill (also: grist mill, corn mill, flour mill, feed mill or feedmill) grinds cereal grain into flour and Wheat middlings, middlings. The term can refer to either the Mill (grinding), grinding mechanism or the building that holds it. Grist i ...

, and

distillery Distillation, or classical distillation, is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distillation is the heati ...

. In the 1920s and 1930s, some people used

dynamite Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay), and Stabilizer (chemistry), stabilizers. It was invented by the Swedish people, Swedish chemist and engineer Alfred Nobel in Geesthacht, Northern Germa ...

to capture fish in Rapid Run. When the logging industry in the area was active, a log dam and a

were constructed on the stream where Halfway Lake currently is. The first stone dam ever built by the

Civilian Conservation Corps The Civilian Conservation Corps (CCC) was a voluntary government work relief program that ran from 1933 to 1942 in the United States for unemployed, unmarried men ages 18–25 and eventually expanded to ages 17–28. The CCC was a major part of ...

impounds Halfway Lake on Rapid Run. A bridge carrying T-400 over Rapid Run was built in 1916 and repaired in 1954. A bridge carrying Pennsylvania Route 192 over the stream was built north of

Cowan Cowan or Cowans may refer to: Places Australia * Cowan, New South Wales * Cowan Creek, a waterway to the north of Sydney, Australia * Division of Cowan, a federal division of the Australian House of Representatives, in Western Australia * Hundr ...

in 1932 and repaired in 1987. A bridge carrying T-383/Walbash Road was built over the stream at End of Narrows in 1935 and repaired in 1958. Another bridge carrying Pennsylvania Route 192 was constructed across the stream in 1936. Three more bridges carrying that highway were built in 1938 and 1939 and repaired in 1986 and 1987. A two-span bridge carrying State Route 1002 was built over the stream west of Mazeppa in 1965. A bridge carrying State Route 3009 was built across the stream northwest of Cowan in 1973 and another bridge carrying that road was built over Rapid Run in Cowan in 1994. The Pennsylvania American Water Company historically owned lands along Rapid Run and considered using the stream as a water supply. However, they eventually sold the land. There are of field lane improvement projects in the watershed. In a 2008 report, the watershed of Rapid Run was ranked fifth amongst sub-watersheds in the Buffalo Creek drainage basin for restoration priority.

Biology

The drainage basin of Rapid Run is designated as a High-Quality Coldwater Fishery and a Migratory Fishery. Wild

trout Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', ''Salmo'' and ''Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salmoni ...

naturally reproduce in the stream from its headwaters downstream to its mouth. It is considered by the

Pennsylvania Fish and Boat Commission The Pennsylvania Fish and Boat Commission is an independent state agency responsible for the regulation of all fishing and boating in the state of Pennsylvania within the United States of America. Unlike many U.S. states, Pennsylvania has a separ ...

to be Class A Wild Trout Waters for

brown trout The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morph ...

from Buffalo Trail downstream to T-383, a distance of .

Brook trout The brook trout (''Salvelinus fontinalis'') is a species of freshwater fish in the char genus ''Salvelinus'' of the salmon family Salmonidae. It is native to Eastern North America in the United States and Canada, but has been introduced elsewhere ...

also inhabit the stream. It has also been stocked with fish. Rapid Run has a population of

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

macroinvertebrates Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate s ...

that has been described as "healthy". Additionally, a freshwater sponge known as '' Spongilla fragilis'' has been observed in the stream, but only near the Halfway Dam. It is likely that physical factors, as opposed to chemical ones, restrict their range. In 2012, the

found two

eel Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 19 families, 111 genera, and about 800 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...

s in Rapid Run, approximately upstream of any eel stocking locations. The eels were between in length. There is a

second-growth forest A secondary forest (or second-growth forest) is a forest or woodland area which has re-grown after a timber harvest or clearing for agriculture, until a long enough period has passed so that the effects of the disturbance are no longer evident. I ...

consisting mainly of

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accep ...

and hemlock. The forest has been described as "pristine". The monthly

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

load in Rapid Run is 5.907 × 10¹⁵ organisms per month. Urban areas contribute 5.579 × 10¹⁵ organisms per month and farm animals contribute 3.210 × 10¹⁴ organisms per month. Wildlife contributes 3.713 × 10¹⁵ organisms per month and septic systems contribute 3.704 × 10¹⁵.

Recreation

Rapid Run has been described as a "high quality" stream with "excellent" angling opportunities. The headwaters of the stream are in

Bald Eagle State Forest Bald Eagle State Forest is a Pennsylvania state forest in Pennsylvania Bureau of Forestry District #7. The main office is located in Laurelton in Union County, Pennsylvania. The forest is found in Centre, Clinton, Mifflin, Snyder, and Union ...

. A reach of it is in R.B. Winter State Park and another reach is in

. A

hiking trail A trail, also known as a path or track, is an unpaved lane or small road usually passing through a natural area. In the United Kingdom and the Republic of Ireland, a path or footpath is the preferred term for a pedestrian or hiking trail. The ...

in the latter park also crosses the stream. According to Mike Sanja's 1988 book ''Pennsylvania Trout & Salmon Fishing Guide'', the best fishing on Rapid Run is in its lower .

References

External links

{{authority control Rivers of Centre County, Pennsylvania Rivers of Union County, Pennsylvania Tributaries of Buffalo Creek (West Branch Susquehanna River) Rivers of Pennsylvania

Course

Tributaries

Hydrology

Geography, geology, and climate

Watershed

History

Biology

Recreation

See also

References

External links