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71-474: The stream is part of a 57.7-square-mile drainage basin , or watershed, in the north-central portion of Fairfax County, Virginia . Difficult Run flows through Great Falls Park , where it has been characterized as "a miniature Mather Gorge and Great Falls ." The stream picks up speed as it runs through a steep gorge with waterfalls, and drains into the Potomac. The wildlife includes 163 species, depending on

142-427: A hierarchical pattern . Other terms for a drainage basin are catchment area , catchment basin , drainage area , river basin , water basin , and impluvium . In North America, they are commonly called a watershed , though in other English-speaking places, "watershed" is used only in its original sense, that of the drainage divide line. A drainage basin's boundaries are determined by watershed delineation ,

213-456: A better, more exciting fight than any other black bass . Rods are usually of ultralight to medium-heavy action. They may also be caught with a fly rod using a dry or wet artificial fly , nymphs, streamers, or imitations of larger aquatic creatures, such as hellgrammites , crawfish, or leeches. Floating topwater popper fly patterns and buzz baits are also popular for smallmouth fishing. For river fishing, spinning tackle or fly tackle has been

284-437: A common task in environmental engineering and science. In a closed drainage basin, or endorheic basin , rather than flowing to the ocean, water converges toward the interior of the basin, known as a sink , which may be a permanent lake, a dry lake , or a point where surface water is lost underground . Drainage basins are similar but not identical to hydrologic units , which are drainage areas delineated so as to nest into

355-454: A drainage basin, and there are different ways to interpret that data. In the unlikely event that the gauges are many and evenly distributed over an area of uniform precipitation, using the arithmetic mean method will give good results. In the Thiessen polygon method, the drainage basin is divided into polygons with the rain gauge in the middle of each polygon assumed to be representative for

426-540: A drainage boundary is referred to as watershed delineation . Finding the area and extent of a drainage basin is an important step in many areas of science and engineering. Most of the water that discharges from the basin outlet originated as precipitation falling on the basin. A portion of the water that enters the groundwater system beneath the drainage basin may flow towards the outlet of another drainage basin because groundwater flow directions do not always match those of their overlying drainage network. Measurement of

497-624: A few paved areas. Hikers, cyclists and horseback riders can make connections using Difficult Run to get to the Fairfax Cross Country Trail . This can be done on the Georgetown Pike end of the Difficult Run trail. Pets are allowed on the trail but must be on a leash at all times. The stream is member to a 57.7- square-mile watershed located in the north-central portion of Fairfax County and drains directly to

568-414: A healthy environment, though they are still much more resilient than most trout species. Carnivorous, its diet comprises crayfish , amphibians , insects , and smaller fish, while the larvae feed on various zooplankton and insect larvae. Adults also cannibalize young of other parents. The female can lay up to 21,100 eggs, which are guarded by the male in his nest. When the weather gets colder, and

639-513: A light yellow-brown and are more oval-shaped. There are two recognized subspecies, the Northern smallmouth bass ( M. dolomieui dolomieui ) and the Neosho smallmouth bass ( M. dolomieui velox ). The Northern smallmouth bass is much more widespread than the much smaller subgroup called the Neosho smallmouth bass. The Neosho are native to an ecologically isolated region of the lower Midwest known as

710-560: A loss of river habitat caused by damming many formerly wild rivers to form lakes or reservoirs. In recent years, a renewed emphasis on preserving water quality and riparian habitat in the nation's rivers and lakes, together with stricter management practices, eventually benefited smallmouth populations and has caused a resurgence in their popularity with anglers. Today, smallmouth bass are very popular game fish , frequently sought by anglers using conventional spinning and bait casting gear, as well as fly fishing tackle. The smallmouth bass

781-602: A multi-level hierarchical drainage system . Hydrologic units are defined to allow multiple inlets, outlets, or sinks. In a strict sense, all drainage basins are hydrologic units but not all hydrologic units are drainage basins. About 48.71% of the world's land drains to the Atlantic Ocean . In North America , surface water drains to the Atlantic via the Saint Lawrence River and Great Lakes basins,

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852-413: A yellowish white ventrally with dark brown vertical bars or blotches along the body and dark brown horizontal bars on the head. The combination of the muscular fusiform body shape and camouflage like coloring make these fish highly effective ambush predators. The coloration can vary greatly depending on the fishes age, habitat, water quality, diet, and the spawning cycle. Generally, the protruding jaw of

923-555: Is a popular game fish sought by anglers throughout the temperate zones of North America , and has been spread by stocking —as well as illegal introductions—to many cool-water tributaries and lakes in Canada and more so introduced in the United States. The maximum recorded size is approximately 27 inches (69 cm) and 12 pounds (5.4 kg). The smallmouth bass is native to the upper and middle Mississippi River basin,

994-867: Is administered by the National Park Service . In addition, almost the entire length of Difficult Run is paralleled by the Cross County Trail, which is maintained by the Fairfax County Park Authority for continuous coverage along the run. The Difficult Run trail enters Great Falls Park and offers views of the Potomac River and Great Falls. The trail is 4.9 miles roundtrip and is estimated to take 2.5 hours. The various trails of Great Falls National Park (Ridge trail, Matildaville trail, Swamp trail, and Old Carriage Road) are also accessible from this hike. The trail

1065-418: Is an area of land in which all flowing surface water converges to a single point, such as a river mouth , or flows into another body of water , such as a lake or ocean . A basin is separated from adjacent basins by a perimeter, the drainage divide , made up of a succession of elevated features, such as ridges and hills . A basin may consist of smaller basins that merge at river confluences , forming

1136-632: Is encouraged that all mess is cleaned, as the park has a no trash policy and has no trash cans available on-site. This is the most popular of recreational activities at the Potomac River adjacent to Difficult Run. Whitewater boating (kayak/canoe) is commonly exercised as the rapids found in Great Falls Park are rated from class II (moderately easy) to class VI. Class VI rapids are considered extremely dangerous, as they are highest category of all rapid classes . A series of rapids starting at

1207-512: Is heavily dependent on latitudinal location. Smallmouth require clean stone, rock, or gravel substrate for a successful spawn. In the United States, smallmouth bass were first introduced outside of their native range with the construction of the Erie Canal in 1825, extending the fish's range into central New York state. During the mid-to-late 19th century, smallmouth were transplanted via the nation's rail system to lakes and rivers throughout

1278-684: Is naturally occurring asbestos fibers that have weathered off of greenstone bedrock . It is a very rare problem but asbestos can be potentially very hazardous if not detected. Soil conservation has rapidly been accelerating in the Difficult Run area for a very long time. This conservation can help stop landslides, corrosion, and contamination by metals All locations are in Fairfax County, Virginia . Pedestrian-only bridges are marked in italics. 38°58′34″N 77°14′06″W  /  38.97611°N 77.23500°W  / 38.97611; -77.23500 Drainage basin A drainage basin

1349-544: Is potentially the toughest fighting freshwater fish in North America, and is commonly the targeted species in many fresh water fishing tournaments. In addition to wild populations, the smallmouth bass is stocked in cool rivers and lakes throughout Canada and the United States. In shallow streams, it is a wary fish, though usually not to the extent of most trout. The smallmouth is highly regarded for its topwater fighting ability when hooked – old fishing journals referred to

1420-487: Is referred to as " watershed management ". In Brazil , the National Policy of Water Resources, regulated by Act n° 9.433 of 1997, establishes the drainage basin as the territorial division of Brazilian water management. When a river basin crosses at least one political border, either a border within a nation or an international boundary, it is identified as a transboundary river . Management of such basins becomes

1491-614: Is the Dead Sea . Drainage basins have been historically important for determining territorial boundaries, particularly in regions where trade by water has been important. For example, the English crown gave the Hudson's Bay Company a monopoly on the fur trade in the entire Hudson Bay basin, an area called Rupert's Land . Bioregional political organization today includes agreements of states (e.g., international treaties and, within

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1562-466: Is well marked with signs that point you to your desired location. Along the trail is the Cow Hoof Rock that is a popular spot for many of the parks rock climbers. While fishing is allowed at Great Falls National Park and Difficult Run, a license is required for fishermen 16 years or older. This section of the Potomac River is known mainly for hosting Smallmouth Bass , Sunfish , and Catfish . It

1633-713: The African Great Lakes , the interiors of Australia and the Arabian Peninsula , and parts in Mexico and the Andes . Some of these, such as the Great Basin, are not single drainage basins but collections of separate, adjacent closed basins. In endorheic bodies of water where evaporation is the primary means of water loss, the water is typically more saline than the oceans. An extreme example of this

1704-672: The Dale Hollow Reservoir , on the Kentucky/Tennessee border, in 1955. In conventional fishing, smallmouth may be successfully caught on a wide range of natural and artificial baits or lures, including crankbaits , hair jigs, plastic jerkbaits, artificial worms, spinnerbaits , and all types of soft plastic lures, including curly tail grubs or tubes with lead head jigs. Spinning reels or baitcasting reels may be used, with line strengths of 6 to 15 pounds typically utilized. According to many, smallmouth typically put up

1775-544: The Eastern Seaboard of the United States, the Canadian Maritimes , and most of Newfoundland and Labrador . Nearly all of South America east of the Andes also drains to the Atlantic, as does most of Western and Central Europe and the greatest portion of western Sub-Saharan Africa , as well as Western Sahara and part of Morocco . The two major mediterranean seas of the world also flow to

1846-735: The Mississippi (3.22 million km ), and the Río de la Plata (3.17 million km ). The three rivers that drain the most water, from most to least, are the Amazon, Ganges , and Congo rivers. Endorheic basin are inland basins that do not drain to an ocean. Endorheic basins cover around 18% of the Earth's land. Some endorheic basins drain to an Endorheic lake or Inland sea . Many of these lakes are ephemeral or vary dramatically in size depending on climate and inflow. If water evaporates or infiltrates into

1917-809: The Nile River ), Southern , Central, and Eastern Europe , Turkey , and the coastal areas of Israel , Lebanon , and Syria . The Arctic Ocean drains most of Western Canada and Northern Canada east of the Continental Divide , northern Alaska and parts of North Dakota , South Dakota , Minnesota , and Montana in the United States, the north shore of the Scandinavian peninsula in Europe, central and northern Russia, and parts of Kazakhstan and Mongolia in Asia , which totals to about 17% of

1988-558: The Potomac River . Along its journey the stream travels over a series of rapids and through numerous rocky beds. There are 9 different streams and tributaries that work into or out of the Potomac river. They are Captain Hickory Run, Piney Run, Colvin Run, Snakeden Branch, Little Difficult Run, Rocky Run, Angelico Branch, Piney Branch , and Wolftrap Creek. The water is crossed by several major highways, including Leesburg Pike, I-66, Route 50,

2059-569: The Saint Lawrence River – Great Lakes system, the Champlain Valley , and the Hudson Bay basin. Its common names include smallmouth , bronzeback , brown bass , brownie , smallie , bronze bass , and bareback bass . Smallmouth have a slender but muscular fusiform body shape making them powerful swimmers. The coloration of the smallmouth bass' ctenoid scales range from golden-olive to dark brown dorsally which fades to

2130-468: The groundwater . A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. Smallmouth bass The smallmouth bass ( Micropterus dolomieu ) is a species of freshwater fish in the sunfish family ( Centrarchidae ) of the order Perciformes . It is the type species of its genus Micropterus ( black basses ), and

2201-789: The Andes. The Indian Ocean 's drainage basin also comprises about 13% of Earth's land. It drains the eastern coast of Africa, the coasts of the Red Sea and the Persian Gulf , the Indian subcontinent , Burma, and most parts of Australia . The five largest river basins (by area), from largest to smallest, are those of the Amazon (7 million km ), the Congo (4 million km ), the Nile (3.4 million km ),

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2272-726: The Atlantic. The Caribbean Sea and Gulf of Mexico basin includes most of the U.S. interior between the Appalachian and Rocky Mountains , a small part of the Canadian provinces of Alberta and Saskatchewan , eastern Central America , the islands of the Caribbean and the Gulf, and a small part of northern South America. The Mediterranean Sea basin, with the Black Sea , includes much of North Africa , east-central Africa (through

2343-628: The Central Interior Highlands, which weave through southwestern Missouri, northern Arkansas and northeastern Oklahoma. They eat tadpoles , fish, aquatic insects, and crayfish . The world record size is 11 pounds 15 ounces (5.41 kg) caught in the Dale Hollow reservoir, on the Kentucky — Tennessee border. The smallmouth bass is found in clearer water than the largemouth, especially streams, rivers, and

2414-584: The Difficult Run Georgetown Pike entrance will lead to directly into the Potomac River. These rapids along the Difficult Run stream range from class III to class V. The Potomac River has many challenging currents, standing waves, and hydraulics. Swimming, wading, and tubing are not allowed in the river. Climbing at Difficult Run can be done both with or without direction. The large number of rocks offer creative options for some park visitors. Others find direction by climbing routes set near

2485-753: The Difficult Run area and water entering Chesapeake Bay . In 1993 Fairfax Relief and the Virginia Soil and water conservation district planted 1,109 native hardwoods as a part of a restoration project on a large flood plain for the main stem of the Difficult run stream. A lot of the soil found in this area is marine clay . This type of soil is found all around Fairfax County and is very problematic. This particular soil contains clays that swell up when wet and then shrink down when they dry. This can cause land slippage, slope instability, poor foundation support and poor drainage. Another soil problem found in this area

2556-507: The Difficult Run trail is located inside of Great Falls Park . Difficult Run lands in the Virginia side of the park. The trail is 0.7 miles one way making it a 1.4 mile round trip. The scenic trail starts near Georgetown Pike and ends where the difficult run stream meets the Potomac River . The trail is narrow and rocky in some sections and could cause problems to those with handicaps . The route consists of mostly non-paved trail systems with

2627-590: The Dulles Access Road, and by the W&;OD Trail. The water runs off and forms four man made lakes. Lake Anne , Lake Fairfax , Lake Thoreau and Lake Audubon . Difficult Run flows through a wide variety of watershed conditions, from forest to urban areas . Just before it empties into the Potomac River, it flows through a narrow, cliff-lined valley. Difficult Run is the largest watershed in Fairfax County, Virginia . There are 41 different soil types found on

2698-507: The Feet (5.10-) Various species of birds, fish, and other animals live along the trail. Muskrat and beaver can be found in the stream which runs adjoined to the trail which empties into the river known to provide habitation for various fish. 163 different species of birds are found here, these birds would include ducks, geese, and herons. Others would include songbirds , woodpeckers , vultures , and kingfishers . As for snakes, copperheads are

2769-785: The Potomac River. Routes vary from 25 to 75 feet in length. All climbing is top rope and no screws may be drilled into the rock. All climbing materials must be supplied by the park goer. Climbing routes are not available when the water level is high, specifically above a 4.5 on the Little Falls gauge. This reading can be found daily in the Washington Post's “River Stages” section. The Cow Hoof Rock features 9 different climbing routes ranging from 5.8 to 5.12 in difficulty. The climbs include: •F.I.S.T. (5.9-) •Hemlock (5.10+) •Hard Nut (A3) •Socrates’ Downfall (5.8) •Claws (5.12) •Titania (5.10-) •Ariel (5.9) •Caliban (5.8) •It's

2840-651: The Spring first, which would consist of the Kentucky warbler . Nested in the trees are the Scarlet Tanager. Other birds native to the trail during the Spring are the Prothonotary warbler and Swallows . During the Spring, Skunk cabbage is the first to bloom in January. Seasonal varieties also include Pink lady slippers , Fairy spuds , and Trout lilies . Located at 38.98 latitude and 77.25 longitude,

2911-623: The US, interstate compacts ) or other political entities in a particular drainage basin to manage the body or bodies of water into which it drains. Examples of such interstate compacts are the Great Lakes Commission and the Tahoe Regional Planning Agency . In hydrology , the drainage basin is a logical unit of focus for studying the movement of water within the hydrological cycle . The process of finding

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2982-406: The basin, it can form tributaries that change the structure of the land. There are three different main types, which are affected by the rocks and ground underneath. Rock that is quick to erode forms dendritic patterns, and these are seen most often. The two other types of patterns that form are trellis patterns and rectangular patterns. Rain gauge data is used to measure total precipitation over

3053-464: The bridge is still visible, but not currently in use. The Thomas Peacock house is still currently located on the eastern part of the Difficult Run. This land was once owned by George Washington. After Washington owned it the Sheppards bought it from him and built the house on this land in the early 19th century. The 18th Century Miller's house stands on the Difficult Run and was built by the miller of

3124-430: The discharge of water from a basin may be made by a stream gauge located at the basin's outlet. Depending on the conditions of the drainage basin, as rainfall occurs some of it seeps directly into the ground. This water will either remain underground, slowly making its way downhill and eventually reaching the basin, or it will permeate deeper into the soil and consolidate into groundwater aquifers. As water flows through

3195-441: The drainage area is dependent on the soil type. Certain soil types such as sandy soils are very free-draining, and rainfall on sandy soil is likely to be absorbed by the ground. However, soils containing clay can be almost impermeable and therefore rainfall on clay soils will run off and contribute to flood volumes. After prolonged rainfall even free-draining soils can become saturated , meaning that any further rainfall will reach

3266-697: The drainage basin to the mouth, and may accumulate there, disturbing the natural mineral balance. This can cause eutrophication where plant growth is accelerated by the additional material. Because drainage basins are coherent entities in a hydrological sense, it has become common to manage water resources on the basis of individual basins. In the U.S. state of Minnesota , governmental entities that perform this function are called " watershed districts ". In New Zealand, they are called catchment boards. Comparable community groups based in Ontario, Canada, are called conservation authorities . In North America, this function

3337-435: The ground and along rivers it can pick up nutrients , sediment , and pollutants . With the water, they are transported towards the outlet of the basin, and can affect the ecological processes along the way as well as in the receiving water body . Modern use of artificial fertilizers , containing nitrogen (as nitrates ), phosphorus , and potassium , has affected the mouths of drainage basins. The minerals are carried by

3408-781: The ground at its terminus, the area can go by several names, such playa, salt flat, dry lake , or alkali sink . The largest endorheic basins are in Central Asia , including the Caspian Sea , the Aral Sea , and numerous smaller lakes. Other endorheic regions include the Great Basin in the United States, much of the Sahara Desert , the drainage basin of the Okavango River ( Kalahari Basin ), highlands near

3479-529: The mill on Hunter Mill Road. Wiley's Tavern is located on the south side of current Leesburg Pike. There are various other sites along the trail, which include Drover's Rest, Old Quarry, Old Dominion Drive Bridge, Colvin Run Village, and Day Family Cemetery. Today the trail is used for hiking, biking, sightseeing, etc. The stream also is known for its various rapids that flow down it. The different rapids are all classified differently as one goes farther down

3550-481: The most popular angling tools for smallmouth in North America for many years. When fishing in colder water, it is believed to be more effective to fish with smaller lures like hair jigs or small spinners. During the rest of the year, smallmouth are usually taken using soft plastic tubes or spinnerbaits. The best spots in rivers to fish for smallmouth are behind rocks or in eddies, where water swirls around. Smallmouth can also be taken in cool lakes like Lake Erie or any of

3621-541: The nation's eastern trout rivers were polluted or experienced elevated water temperatures, reducing the range of native brook trout . Smallmouth bass were often introduced to northern rivers with increased water temperatures and slowly became a popular gamefish with many anglers. Equally adaptable to large, cool-water impoundments and reservoirs, the smallmouth also spread far beyond its original native range. Later, smallmouth populations also began to decline after years of damage caused by overdevelopment and pollution, as well as

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3692-576: The northern and western United States, as far as California. Shippers found that smallmouth bass were a hardy species that could be transported in buckets or barrels by rail, sometimes using the spigots from the railroad water tanks to aerate the fingerlings. They were introduced east of the Appalachians just before the Civil War, and afterwards transplanted to the states of New England. With increased industrialization and land use changes, many of

3763-521: The only type of venomous snake found in the trail. In the region where Difficult Run trail is found, birds such as the Scarlet Tanager and Kentucky Warbler inhabit the environment during the Spring months. These birds migrate North to live for the Summer, which includes Fairfax County. These are song birds brightly colored with plumage of gold, red, and blue. The ground nesting birds appear in

3834-418: The rainfall on the area of land included in its polygon. These polygons are made by drawing lines between gauges, then making perpendicular bisectors of those lines form the polygons. The isohyetal method involves contours of equal precipitation are drawn over the gauges on a map. Calculating the area between these curves and adding up the volume of water is time-consuming. Isochrone maps can be used to show

3905-631: The responsibility of the countries sharing it. Nile Basin Initiative , OMVS for Senegal River , Mekong River Commission are a few examples of arrangements involving management of shared river basins. Management of shared drainage basins is also seen as a way to build lasting peaceful relationships among countries. The catchment is the most significant factor determining the amount or likelihood of flooding . Catchment factors are: topography , shape, size, soil type, and land use (paved or roofed areas). Catchment topography and shape determine

3976-461: The river rather than being absorbed by the ground. If the surface is impermeable the precipitation will create surface run-off which will lead to higher risk of flooding; if the ground is permeable, the precipitation will infiltrate the soil. Land use can contribute to the volume of water reaching the river, in a similar way to clay soils. For example, rainfall on roofs, pavements , and roads will be collected by rivers with almost no absorption into

4047-413: The rocky areas and stumps and also sandy bottoms of lakes and reservoirs. It can also survive in a stronger current than other black bass. The smallmouth prefers cooler water temperatures than its cousin the largemouth bass , and as a result will often seek out deeper, faster moving water during the hot summer months. Because it is intolerant of pollution , the smallmouth bass is a good natural indicator of

4118-479: The season, and 41 soil types are found on the trail and alongside the stream. Used for many purposes since the early 1800s, the area is today used for hiking, biking, fishing, boating, climbing, and bird watching. It was named by long-boatmen in the time of the Patowmack Company , who found the two sharp bends of the Potomac near Difficult Run's mouth treacherous. Tolston's Mill on the east side of

4189-412: The smallmouth bass as "ounce for ounce and pound for pound the gamest fish that swims". Smallmouth bass are not usually taken for the table, but rather are caught and released by most anglers. However, smaller specimens in cooler water often have higher quality filets of white, firm flesh when cooked. The current all-tackle world record for a smallmouth bass is 11 lb 15 oz, caught by David Hayes in

4260-878: The smallmouth does not extend back beyond the eyes which are red or brown. They have two dorsal fins which are separated by a shallow interdorsal notch. The front dorsal has 9–11 spiney rays and the back dorsal has 13–15 soft rays. Males are generally smaller than females. The males tend to range around two pounds, while females can range from three to six pounds. Their average sizes and coloration can differ, depending on if they are found in lacustrine or riverine habitats. Smallmouth found in riverine habitats are generally long and slender which allows greater agility in moving water, while those found in lacustrine habitats and shorter and deeper bodied. Riverine smallmouth that live in dark water tend to be rather torpedo-shaped and very dark brown to be more efficient for feeding. Lacustrine smallmouth bass, however, that live in sandy areas, tend to be

4331-418: The speed with which the runoff reaches a river. A long thin catchment will take longer to drain than a circular catchment. Size will help determine the amount of water reaching the river, as the larger the catchment the greater the potential for flooding. It is also determined on the basis of length and width of the drainage basin. Soil type will help determine how much water reaches the river. The runoff from

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4402-466: The stream. The seven rapids that occur in the stream all have classifications that range from Class III to V. The Difficult Run is also famously known for its views of the Potomac and Mather Gorge cliffs. Recreational activities at Difficult Run include hiking, biking, climbing, boating, fishing, and sightseeing. The watershed itself encompasses a few parks and trails originating in Reston and reaching all

4473-415: The time taken for rain to reach the river, while catchment size, soil type, and development determine the amount of water to reach the river. Generally, topography plays a big part in how fast runoff will reach a river. Rain that falls in steep mountainous areas will reach the primary river in the drainage basin faster than flat or lightly sloping areas (e.g., > 1% gradient). Shape will contribute to

4544-477: The time taken for runoff water within a drainage basin to reach a lake, reservoir or outlet, assuming constant and uniform effective rainfall. Drainage basins are the principal hydrologic unit considered in fluvial geomorphology . A drainage basin is the source for water and sediment that moves from higher elevation through the river system to lower elevations as they reshape the channel forms. Drainage basins are important in ecology . As water flows over

4615-472: The trail and alongside the stream. Two major soil groups make up the contents: The Glenelg-Elioak-Manor association and the Manor-Glenelg-Elioak association. The Glenelg soil type makes up 40.5 percent of the watershed area and is found throughout the watershed, primarily on hilltops and side slopes. Manor soils make up almost 11 percent of the watershed. Suspended sediment is a major problem in

4686-623: The trail is today owned by the Madeira School . Leigh Mill, once on the west side of the trail, ground flour during the late 1800s. Colvin's Mill, today part of Colvin Run Mill Park, used to be managed by Fairfax County Park Authority. Brown's Mill was on a tributary of the trail across from Beulah Road. Old Georgetown Pike developed into a state highway in June 1974. The pike was a route followed by colonists and Indians where commerce

4757-490: The trail that sees the most mountain biking activity starts near the end of Michael Faraday Court, behind SkateQuest-Reston ice skating rink and follows the tributary stream valley to Lake Fairfax. From Lake Fairfax the trail crosses over Hunter Mill Road and follows Difficult Run itself all the way to Great Falls Park. Great Falls Park is a unit of the George Washington Memorial Parkway , and

4828-577: The water temperature drops below 15 C (60 F), smallmouth will often migrate in search of deeper pools in which they enter a semi-hibernation state, moving sluggishly and feeding very little until the warm season returns. The migration patterns of smallmouth have been tracked and it is not unusual for a smallmouth to travel 12 miles in a single day in a stream, creek or river. The overall migration can exceed 60 miles. Smallmouth generally begin spawning patterns in spring or early summer when water temperatures are between 15–18 °C (59.0–64.4 °F), which

4899-580: The way to the Potomac River, at the end of the Difficult Run trail in Great Falls. Additionally, Difficult Run offers access to Great Falls National Park from certain areas of the trail, adding to the options for recreational activity. Using community planning, a secluded 12-mile (19 km) hiking and biking trail was built along Difficult Run from Reston to Great Falls Park. The trail is well known among area mountain biking enthusiasts for its rolling terrain which makes for fast, smooth rides although there are portions requiring technical skills. The portion of

4970-468: The world's land. Just over 13% of the land in the world drains to the Pacific Ocean . Its basin includes much of China, eastern and southeastern Russia, Japan, the Korean Peninsula , most of Indochina, Indonesia and Malaysia, the Philippines, all of the Pacific Islands , the northeast coast of Australia , and Canada and the United States west of the Continental Divide (including most of Alaska), as well as western Central America and South America west of

5041-405: Was brought from Loudoun County and the Shenandoah Valley to Georgetown. Another road that went along the trail is the Old Leesburg Pike. This pike initially went through the Difficult Run on the northern side of the current bridge. General Braddock utilized the old highway during the French and Indian Wars where he marched his troops throughout the road on their way to Fort Duquesne. The old access to

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