Seymouriamorpha were a small but widespread group of limbed vertebrates. They have long been considered reptiliomorphs, most paleontologists may still accept this point of view, but some analyses suggest that seymouriamorphs are stem-tetrapods. Many seymouriamorphs were semi-aquatic. However, aquatic larvae bearing external gills and grooves from the lateral line system have been found, making them unquestionably amphibians; the adults were terrestrial. They ranged from lizard-sized creatures to crocodile-sized 150 centimeter long animals, they were reptile-like. If seymouriamorphs are reptiliomorphs, they were the distant relatives of amniotes. Seymouriamorphs form into three main groups, Kotlassiidae and Seymouriidae, a group that includes the best known genus, Seymouria; the last seymouriamorph became extinct by the end of Permian. Reptiliomorpha Order Seymouriamorpha Biarmica Enosuchus Kotlassia Leptoropha Microphon Nyctiboetus Utegenia Waggoneria Family Karpinskiosauridae Karpinskiosaurus Family Discosauriscidae Ariekanerpeton Discosauriscus Makowskia Spinarerpeton Family Seymouriidae SeymouriaCladogram based on Ruta, Jeffery, & Coates: Cladogram based on Klembara & Klembara: Bystrow, A.
P. Kotlassia prima Amalitzky. Bulletin of the Geological Society of America, Washington, 1944, v.55, N5, pp.379-416. Seymouriamorpha - at Paleos Seymouriamorpha at Tree of Life Web Project
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of small particules and subsequent cementation of mineral or organic particles on the floor of oceans or other bodies of water at the Earth's surface. Sedimentation is the collective name for processes; the particles that form a sedimentary rock are called sediment, may be composed of geological detritus or biological detritus. Before being deposited, the geological detritus was formed by weathering and erosion from the source area, transported to the place of deposition by water, ice, mass movement or glaciers, which are called agents of denudation. Biological detritus was formed by bodies and parts of dead aquatic organisms, as well as their fecal mass, suspended in water and piling up on the floor of water bodies. Sedimentation may occur as dissolved minerals precipitate from water solution; the sedimentary rock cover of the continents of the Earth's crust is extensive, but the total contribution of sedimentary rocks is estimated to be only 8% of the total volume of the crust.
Sedimentary rocks are only a thin veneer over a crust consisting of igneous and metamorphic rocks. Sedimentary rocks are deposited in layers as strata; the study of sedimentary rocks and rock strata provides information about the subsurface, useful for civil engineering, for example in the construction of roads, tunnels, canals or other structures. Sedimentary rocks are important sources of natural resources like coal, fossil fuels, drinking water or ores; the study of the sequence of sedimentary rock strata is the main source for an understanding of the Earth's history, including palaeogeography and the history of life. The scientific discipline that studies the properties and origin of sedimentary rocks is called sedimentology. Sedimentology is part of both geology and physical geography and overlaps with other disciplines in the Earth sciences, such as pedology, geomorphology and structural geology. Sedimentary rocks have been found on Mars. Sedimentary rocks can be subdivided into four groups based on the processes responsible for their formation: clastic sedimentary rocks, biochemical sedimentary rocks, chemical sedimentary rocks, a fourth category for "other" sedimentary rocks formed by impacts and other minor processes.
Clastic sedimentary rocks are composed of other rock fragments that were cemented by silicate minerals. Clastic rocks are composed of quartz, rock fragments, clay minerals, mica. Clastic sedimentary rocks, are subdivided according to the dominant particle size. Most geologists use the Udden-Wentworth grain size scale and divide unconsolidated sediment into three fractions: gravel and mud; the classification of clastic sedimentary rocks parallels this scheme. This tripartite subdivision is mirrored by the broad categories of rudites and lutites in older literature; the subdivision of these three broad categories is based on differences in clast shape, grain size or texture. Conglomerates are dominantly composed of rounded gravel, while breccias are composed of dominantly angular gravel. Sandstone classification schemes vary but most geologists have adopted the Dott scheme, which uses the relative abundance of quartz and lithic framework grains and the abundance of a muddy matrix between the larger grains.
Composition of framework grains The relative abundance of sand-sized framework grains determines the first word in a sandstone name. Naming depends on the dominance of the three most abundant components quartz, feldspar, or the lithic fragments that originated from other rocks. All other minerals are considered accessories and not used in the naming of the rock, regardless of abundance. Quartz sandstones have >90% quartz grains Feldspathic sandstones have <90% quartz grains and more feldspar grains than lithic grains Lithic sandstones have <90% quartz grains and more lithic grains than feldspar grainsAbundance of muddy matrix material between sand grains When sand-sized particles are deposited, the space between the grains either remains open or is filled with mud. "Clean" sandstones with open pore space are called arenites. Muddy sandstones with abundant muddy matrix are called wackes. Six sandstone names are possible using the descriptors for grain composition and the amount of matrix. For example, a quartz arenite would be composed of quartz grains and have little or no clayey matrix between the grains, a lithic wacke would have abundant lithic grains and abundant muddy matrix, etc.
Although the Dott classification scheme is used by sedimentologists, common names like greywacke and quartz sandstone are still used by non-specialists and in popular literature. Mudrocks are sedimentary rocks composed of at least 50% silt- and clay-sized particles; these fine-grained particles are transported by turbulent flow in water or air, deposited as the flow calms and the particles settle out of suspension. Most authors presently
Wichita Falls, Texas
Wichita Falls is a city in and the county seat of Wichita County, United States. It is the principal city of the Wichita Falls Metropolitan Statistical Area, which encompasses all of Archer and Wichita Counties. According to the 2010 census, it had a population of 104,553, making it the 38th-most populous city in Texas. In addition, its central business district is 5 miles from Sheppard Air Force Base, home to the Air Force's largest technical training wing and the Euro-NATO Joint Jet Pilot Training program, the world's only multinationally staffed and managed flying training program chartered to produce combat pilots for both USAF and NATO; the city is home to the Newby-McMahon Building, constructed downtown in 1919 and featured in Robert Ripley's Ripley's Believe It or Not!. The Choctaw Native Americans settled the area in the early 19th century from their native Mississippi area once Americans negotiated to relocate them after the Treaty of Dancing Rabbit Creek. American settlers arrived in the 1860s to form cattle ranches.
The city was titled Wichita Falls on September 27, 1872. On that day, a sale of town lots was held at what is now the corner of Seventh and Ohio Streets – the birthplace of the city; the Fort Worth & Denver City Railway arrived in September 1882, the same year the city became the county seat of Wichita County. The city grew westwards from the original FW&DC train depot, located at the northwest corner of Seventh Street and the FW&DC; this area is now referred to as the Depot Square Historic District, declared a Texas Historic Landmark. The early history of Wichita Falls well into the 20th century rests on the work of two entrepreneurs, Joseph A. Kemp and his brother-in-law, Frank Kell. Kemp and Kell were pioneers in food processing and retailing, flour milling, cattle and oil. A flood in 1886 destroyed. After nearly 100 years of visitors wanting to visit the nonexistent falls, the city built an artificial waterfall beside the river in Lucy Park; the recreated falls are recirculate at 3,500 gallons per minute.
They are visible to south-bound traffic on Interstate 44. The city is seeking funding to rebuild and restore the downtown area. Downtown Wichita Falls was the city's main shopping area for many years, but lost ground to the creation of new shopping centers throughout the city beginning with Parker Square in 1953 and other similar developments during the 1960s and 1970s, culminating with the opening of Sikes Senter Mall in 1974. Wichita Falls was once home to offices of several oil companies and related industries, along with oil refineries operated by the Continental Oil Company until 1952 and Panhandle Oil Company American Petrofina) until 1965. Both firms continued to use a portion of their former refineries as gasoline/oil terminal facilities for many years. A devastating tornado hit the north and northwest portions of Wichita Falls along with Sheppard Air Force Base during the afternoon of April 3, 1964; as the first violent tornado on record to hit the Wichita Falls area, it left seven dead and more than 100 injured.
Additionally, the tornado caused $15 million in property damage with about 225 homes destroyed and another 250 damaged. It was rated as an F5, the highest rating on the Fujita scale, but it is overshadowed by the 1979 tornado. An F4 tornado struck the populated southern sections of Wichita Falls in the late afternoon on Tuesday, April 10, 1979, it was part of an outbreak. Despite having nearly an hour's advance warning that severe weather was imminent, 42 people were killed and 1,800 were injured because it arrived just in time for many people to be driving home from work, it left 20,000 people homeless and caused $400 million in damage, a U. S. record not topped by an individual tornado until the F5 Moore-Oklahoma City tornado of May 3, 1999. Wichita Falls is about 15 miles south of the border with Oklahoma, 115 mi northwest of Fort Worth, 140 mi southwest of Oklahoma City. According to the United States Census Bureau, the city has a total area of 70.71 square miles, of which 70.69 square miles are land and 0.02 square miles is covered by water.
Wichita Falls experiences a humid subtropical climate, featuring long hot and humid summers, cool winters. The city has some of the highest summer daily maximum temperatures in the entire U. S. outside of the Desert Southwest. Temperatures have hit 100 °F as early as March 27 and as late as October 17, but more reach that level on 28 days annually, with 102 days of 90 °F or higher annually. However, 59 to 60 nights of freezing lows occur, an average of 4.8 days where the high does not rise above freezing. The monthly daily average temperature ranges from 42.0 °F in January to 84.4 °F in July. Extremes in temperature have ranged from −12 °F on January 4, 1947, to 117 °F on June 28, 1980. Snowfall is sporadic and averages 4.1 in per season, while rainfall is greatest in early summer. In September 2011, Wichita Falls became the first Texas city to have 100 days of 100 °F in one year. During the 2015 Texas–Oklahoma floods, Wichita Falls broke its all-time record for the wettest month, with 17.00 inches of rain recorded in May 2015.
Wichita Falls is no longer experiencing drought conditions. During a three-week period in May 2015, 17 inches of rain
Seymouria was a reptile-like tetrapod from the early Permian of North America and Europe. It was small, only 2 ft long. Seymouria was well adapted to life on land, with many reptilian features—so many, in fact, that it was first thought to be a primitive reptile. Seymouria individuals were robustly built animals, with a large head, short neck, stocky limbs, broad feet; the skull was boxy and triangular when seen from above, but it was lower and longer than that of most other seymouriamorphs. The vertebrae had swollen neural arches; as a whole the body shape was similar to that of contemporary reptiles and reptile-like tetrapods such as captorhinids and parareptiles. Collectively these types of animals have been referred to as "cotylosaurs" in the past, although they do not form a clade; the skull was composed of many smaller plate-like bones. The configuration of skull bones present in Seymouria was similar to that of far more ancient tetrapods and tetrapod relatives. For example, it retains an intertemporal bone, the plesiomorphic condition present in animals like Ventastega and embolomeres.
The skull bones were textured, as was typical for ancient amphibians and captorhinid reptiles. In addition, the rear part of the skull had a large incision stretching along its side; this incision has been termed an otic notch, a similar incision in the same general area is common to most Paleozoic amphibians, but unknown in amniotes. The lower edge of the otic notch was formed by the squamosal bone, while the upper edge was formed by downturned flanges of the supratemporal and tabular bones; the tabular has a second downturned flange visible from the rear of the skull. The development of the otic and occipital flanges is greater in Seymouria than in any other seymouriamorph; the sensory apparatus of the skull deserves mention for an array of unique features. The orbits were about midway down the length of the skull, although they were a bit closer to the snout in juveniles, they were more rhomboidal than the circular orbits of other seymouriamorphs, with an acute front edge. Several authors have noted that a few specimens of Seymouria possessed indistinct grooves present in bones surrounding the orbits and in front of the otic notch.
These grooves were remnants of a lateral line system, a web of pressure-sensing organs useful for aquatic animals, including the presumed larval stage of Seymouria. Many specimens do not retain any remnant of their lateral lines, not juveniles. In the middle of the parietal bones was a small hole known as a pineal foramen, which may have held a sensory organ known as a parietal eye; the pineal foramen is smaller in Seymouria than in other seymouriamorphs. The stapes, a rod-like bone which lies between the braincase and the wall of the skull, was tapered, it connected the braincase to the upper edge of the otic notch, served as a conduit of vibrations received by a tympanum which lied within the otic notch. In this way it could transmit sound from the outside world to the brain; the configuration of the stapes is intermediate between non-amniote amniotes. On the one hand, its connection to the otic notch is unusual, since true reptiles and other amniotes have lost an otic notch, forcing the tympanum and stapes to shift downwards towards the quadrate bone of the jaw joint.
On the other hand, the thin, sensitive structure of Seymouria's stapes is a specialization over most non-amniote tetrapods, which have a thick stapes useless for hearing yet useful for reinforcing the skull. The palate had some similarities with both non-amniote tetrapods. On the one hand, it retained a few isolated fangs with maze-like internal enamel folding, as is characteristic for "labyrinthodont" amphibians. On the other hand, the vomer bones at the front of the mouth were narrow, the adjacent choanae were large and close together, as in amniotes; the palate is solid bone, with only vestigial interpteryoid vacuities separated by a long and thin cultriform process. Apart from the isolated fangs, the palate is covered with small denticles radiating out from the rear part of the pterygoid bones. Seymouria has a few amniote-like characteristics of the palate, such as the presence of a prong-like branch of the pterygoid as well as an epipterygoid bone, separate from the pterygoid. However, these characteristics have been observed in various non-amniote tetrapods, so they do not signify its status as an amniote.
The lower jaw retained a few plesiomorphic characteristics. For example, the inner edge of the mandible possessed three coronoid bones; the mandible retained at least one large hole along its inner edge known as a meckelian fenestra, although this feature was only confirmed during a 2005 re-investigation of one of the Cutler Formation specimens. Neither of these traits are common in amniotes; the braincase had a mosaic of features in common with various tetrapodomorphs. The system of grooves and nerve openings on the side of the braincase were unusually similar to those of the fish Megalichthys, the cartilaginous base is another plesiomorphic feature. However, the internal carotid arteries perforate the bra
A ZIP Code is a postal code used by the United States Postal Service in a system it introduced in 1963. The term ZIP is an acronym for Zone Improvement Plan; the basic format consists of five digits. An extended ZIP+4 code was introduced in 1983 which includes the five digits of the ZIP Code, followed by a hyphen and four additional digits that reference a more specific location; the term ZIP Code was registered as a servicemark by the U. S. Postal Service, but its registration has since expired; the early history and context of postal codes began with postal district/zone numbers. The United States Post Office Department implemented postal zones for numerous large cities in 1943. For example: The "16" was the number of the postal zone in the specific city. By the early 1960s, a more organized system was needed, non-mandatory five-digit ZIP Codes were introduced nationwide on July 1, 1963; the USPOD issued its Publication 59: Abbreviations for Use with ZIP Code on October 1, 1963, with the list of two-letter state abbreviations which are written with both letters capitalized.
An earlier list in June had proposed capitalized abbreviations ranging from two to five letters. According to Publication 59, the two-letter standard was "based on a maximum 23-position line, because this has been found to be the most universally acceptable line capacity basis for major addressing systems", which would be exceeded by a long city name combined with a multi-letter state abbreviation, such as "Sacramento, Calif." along with the ZIP Code. The abbreviations have remained unchanged, with the exception of Nebraska, changed from NB to NE in 1969 at the request of the Canadian postal administration, to avoid confusion with the Canadian province of New Brunswick. Robert Moon is considered the father of the ZIP Code; the post office only credits Moon with the first three digits of the ZIP Code, which describe the sectional center facility or "sec center." An SCF is a central mail processing facility with those three digits. The fourth and fifth digits, which give a more precise locale within the SCF, were proposed by Henry Bentley Hahn Sr.
The SCF sorts mail to all post offices with those first three digits in their ZIP Codes. The mail is sorted according to the final two digits of the ZIP Code and sent to the corresponding post offices in the early morning. Sectional centers do not deliver mail and are not open to the public, most of their employees work the night shift. Mail picked up at post offices is sent to their own SCF in the afternoon, where the mail is sorted overnight. In the case of large cities, the last two digits coincide with the older postal zone number thus: In 1967, these became mandatory for second- and third-class bulk mailers, the system was soon adopted generally; the United States Post Office used a cartoon character, which it called Mr. ZIP, to promote the use of the ZIP Code, he was depicted with a legend such as "USE ZIP CODE" in the selvage of panes of postage stamps or on the covers of booklet panes of stamps. In 1971 Elmira Star-Gazette reporter Dick Baumbach found out the White House was not using a ZIP Code on its envelopes.
Herb Klein, special assistant to President Nixon, responded by saying the next printing of envelopes would include the ZIP Code. In 1983, the U. S. Postal Service introduced an expanded ZIP Code system that it called ZIP+4 called "plus-four codes", "add-on codes", or "add-ons". A ZIP+4 Code uses the basic five-digit code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a city block, a group of apartments, an individual high-volume receiver of mail, a post office box, or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery. However, initial attempts to promote universal use of the new format met with public resistance and today the plus-four code is not required. In general, mail is read by a multiline optical character reader that instantly determines the correct ZIP+4 Code from the address—along with the more specific delivery point—and sprays an Intelligent Mail barcode on the face of the mail piece that corresponds to 11 digits—nine for the ZIP+4 Code and two for the delivery point.
For Post Office Boxes, the general rule is. The add-on code is one of the following: the last four digits of the box number, zero plus the last three digits of the box number, or, if the box number consists of fewer than four digits, enough zeros are attached to the front of the box number to produce a four-digit number. However, there is no uniform rule, so the ZIP+4 Code must be looked up individually for each box; the ZIP Code is translated into an Intelligent Mail barcode, printed on the mailpiece to make it easier for automated machines to sort. A barcode can be printed by the sender, it is better to let the post office put one on. In general, the post office uses OCR technology, though in some cases a human might have to read and enter the address. Customers who send bulk mail can get a discount on postage if they have printed the barcode themselves and have presorted the mai
Geology and hydrology of the Wichita Falls, Texas area
The exposed strata at the surface in and around Wichita Falls are the products of one ancient period of deposition with a modest amount of recent and modern alteration. In all cases, the strata are products of terrigenous environments dominated by fluvial depositional and erosional systems; the rocks found in and around Wichita Falls result from southwesterly-flowing Permian streams that deposited sands in channels and silts and clays on the surrounding floodplains. Calcium-carbonate rich soils concurrently developed adjacent to these streams; these were buried by further Permian sedimentation and lithified. Pleistocene erosion removed the younger rocks. Exposures of sediments indicate that northeast-flowing streams locally deposited silts, clays and some gravels on the Permian rocks; these are subsequently modified by deposition. In the Permian geologic period, North-Central Texas was a part of the western coastal zone of equatorial Pangea, a super-continental land mass. Nearby uplifts and mountainous regions, such as the Muenster Arch and Red River Uplift, the Wichita and Ouachita mountains developed by the end of the Pennsylvanian, providing elevated topography to the north and east during the Permian.
The rocks of the Permian Basin of West Texas record a contemporaneous shallow inland sea. The resulting topography provided northeast-to-southwest gradients for stream flow and sediment movement; the sediments deposited by the Permian streams of North-Central Texas were reworked clastic materials from Middle Pennsylvanian stream and fan-delta sediments proximal to the Ouachita foldbelt and Muenster Highlands. The Petrolia Formation dominates the exposed Permian strata in Wichita falls, as mapped by the 1987 Texas Atlas of Geology; the map describes the formation as 360–400 feet of weakly or unstratified mudstone with laminated, cross-bedded sandstone lenses. The formation increases in mudstone content upsection. Sandstone lenses contain terrestrial fossils of plants and footprints; the unit contains calcareous nodules of varying sizes as well as poorly indurated "conglomerate" with vertebrate fossils. In general the entire package is only weakly lithified indicating that the region was not appreciably covered by a thick package of younger strata.
Several correlated sandstone units crop out in the immediate region. These dominate the region adjacent to the Seymour Highway, on the slopes to the south of the Wichita River; the Texas Atlas of Geology mapped these as ss6. Most outcrops are buff-colored, well-sorted quartzose sandstones; these exhibit extensive cross-bedding and soft-sediment deformation features. Some deposits are friable. Locally, there appears to be three prominent layers of sandstone separated by mudstone; because of variable erosion rates, each influences topography by forming ledges and benches, in places may form mesa-like landforms. In and around the city, these occur at 960, 1000, 1060 feet above sea level. Up to 30 feet of fluvial deposits of unconsolidated gravel and silt mapped as terrace deposition by the 1987 Texas Atlas of Geology. Gravels are granule-to-cobble size, with clasts of angular to well-rounded quartzite and chert from distal sources and lesser fragments of local strata; the sands are fine - to coarse-grained with preserved soils.
Up to 30 feet of floodplain and channel sand, silt and gravel from the modern stream systems. This includes terrace deposits near floodplain, colluvium on valley slopes, local wind-blown sand and silt; the region is underlain with shallowly west-dipping strata, but a significant uplifted block is found in the subsurface north of Wichita Falls. This block, locally known as the Red River uplift, may be part of an uplifted system that extends eastward, joining the Muenster Arch; the uplifts offset Pennsylvanian and older strata in the subsurface and are thought to be contemporaneous with the Ouachita and Ancestral Rocky Orogenies. These Pennsylvanian orogenies resulted from the closure of the Iapetus ocean as the Gondwana and Laurentia continents collided to form Pangea. Petroleum resources were discovered in the region in the early 1900s, the area remains a locus of exploration and production. Groundwater in Wichita Falls is drawn from the Seymour aquifer or from alluvial aquifers associated with local streams.
Groundwater withdrawals are limited to individual property owners and do not feed into the municipal supply for the city of Wichita Falls. However, the nearby city of Burkburnett, located 15 miles north of Wichita Falls relies in part on this aquifer for municipal supply; the Seymour aquifer may be locally confined under clay-rich sediments. In the southern part of the city, the distribution and nature of the aquifer is consistent with one hosted by Pleistocene and/or Holocene fluvial channel deposits; the depth to water averages 14 feet below the surface correlated with topography. The water is sourced in coarse sands and gravels 10-19' below the surface. Dry holes in this same area contain no sand-gravel layers within the first 22 feet; the horizontal distribution of this shallow aquifer is irregular. Seymour aquifer groundwater once fed the Cedar Springs Pools, a popular recreational public swimming facility in the 1930s and 40s; the two pools were located between Taft Boulevard and Robin Lane north of Hampstead Rd. in the southern part of Wichita Falls.
Long-time residents hav
The Brazos River, called the Río de los Brazos de Dios by early Spanish explorers, is the 11th-longest river in the United States at 1,280 miles from its headwater source at the head of Blackwater Draw, Curry County, New Mexico to its mouth at the Gulf of Mexico with a 45,000-square-mile drainage basin. Being one of Texas' largest rivers, it is sometimes used to mark the boundary between East Texas and West Texas; the river is associated with Texas history the Austin settlement and Texas Revolution eras. Today major Texas institutions like Texas A&M University and Baylor University are located close to the river, as are parts of metropolitan Houston; the Brazos proper begins at the confluence of the Salt Fork and Double Mountain Fork, two tributaries of the Upper Brazos that rise on the high plains of the Llano Estacado, flowing 840 miles southeast through the center of Texas. Another major tributary of the Upper Brazos is the Clear Fork Brazos River, which passes by Abilene and joins the main river near Graham.
Important tributaries of the Lower Brazos include the Paluxy River, the Bosque River, the Little River, Yegua Creek, the Nolan River, the Leon River, the San Gabriel River, the Lampasas River, the Navasota River. Running east towards Dallas-Fort Worth, the Brazos turns south, passing through Waco and the Baylor University campus, further south to near Calvert, Texas past Bryan and College Station through Richmond, Texas in Fort Bend County, empties into the Gulf of Mexico in the marshes just south of Freeport; the main stem of the Brazos is dammed in three places, all north of Waco, forming Possum Kingdom Lake, Lake Granbury, Lake Whitney. Of these three, Granbury was the last to be completed, in 1969; when its construction was proposed in the mid-1950s, John Graves wrote the book Goodbye to a River. The Whitney Dam, located on the upper Brazos, provides hydroelectric power, flood control, irrigation to enable efficient cotton growth in the river valley. A small municipal dam is near the downstream city limit of Waco at the end of the Baylor campus.
This impoundment of the Brazos through Waco is locally called Lake Brazos. A total of nineteen major reservoirs are located along the Brazos. In 1822, the lower river valley of the Brazos River became one of the major Anglo-American settlement sites in Texas; this was one of the first English-speaking colonies along the Brazos and was founded by Stephen F. Austin at San Felipe de Austin. In 1836, Texas declared independence from Mexico at Washington-on-the-Brazos, a settlement in now Washington County, known as "the birthplace of Texas". Brazos River was the scene of a battle between the Texas Navy and Mexican Navy during the Texas Revolution. Texas Navy ship, it is unclear when it was first named by European explorers, since it was confused with the Colorado River not far to the south, but it was seen by René-Robert Cavelier, Sieur de La Salle. Spanish accounts call it Los Brazos de Dios, for which name there were several different explanations, all involving it being the first water to be found by thirsty parties.
In 1842, Indian commissioner of Texas, Ethan Stroud established a trading post on this river. The river was important for navigation before and after the American Civil War, steam boats sailed as far up the river as Washington-on-the-Brazos. While attempts to improve commercial navigation on the river continued, railroads proved more reliable; the Brazos River flooded seriously, on a regular basis before a piecemeal levee system was replaced, notably in 1913 when a massive flood affected the course of the river. The river is important today as a source of water for power and recreation; the water is administered by the Brazos River Authority. The 2000 book and Sternwheelers: Steam Navigation on the Brazos by Pamela A. Puryear and Nath Winfield, Jr. with introduction by J. Milton Nance, examines the early vessels that attempted to navigate the Brazos. On June 2, 2016, the rising of the river required evacuations for portions of Brazoria County; the Brazos River watershed covers a total area of 119,174 square kilometers.
Within the watershed lie 42 lakes and rivers which have a combined storage capacity of 2.5 million acre-feet. The Brazos watershed has an estimated ground water availability of 119,275 acre-feet per year. 31% of the land use within the watershed is cropland. 61% is grassland shrubland and forest while urban use only makes up 4.6%. The population density within the watershed is 19.5 people per square kilometer. The main water quality issues within the Brazos Watershed are high nutrient loads, high bacterial and salinity levels and low dissolved oxygen; these water quality issues can be attributed to livestock and chemical run off. Sources of run off are croplands and industrial sites among others. Fracking is cause for concern regarding water quality within the Brazos Watershed; the Barnett Shale lies within the watershed, the second largest source of natural gas in the US. Studies have shown that the watershed receiving the most toxic pollution is the lower Brazos river which received 33.4 million pounds of toxic waste in 2012.
Canoeing is a popular recreational activity on the Brazos River with many locations favorable for launching and recovery. The best paddling can be found below Possum Kingdom Lake and Lake Granbury. Sandbar Camping is permitted since the entire streambed of t