San Marcos is a city and the county seat of Hays County, Texas, United States. The city is a part of the Greater Austin Metropolitan Area. San Marcos's limits extend into Caldwell and Guadalupe counties, as well. San Marcos is on the Interstate 35 corridor between Austin and San Antonio. Its population was 44,894 at the 2010 census and 67,553 at the 2020 census. Founded on the banks of the San Marcos River, the area is thought to be among the oldest continuously inhabited sites in the Americas. San Marcos is home to Texas State University and the Meadows Center for Water and the Environment.
Barton Springs is a set of four natural water springs located at Barton Creek on the grounds of Zilker Park in Austin, Texas, resulting from water flowing through the Edwards Aquifer. The largest spring, Main Barton Spring, supplies water to Barton Springs Pool, a popular recreational destination in Austin. The smaller springs are located nearby, two with man-made structures built to contain and direct their flow. The springs are the only known habitat of the Barton Springs Salamander, an endangered species.
The Barton Springs salamander is an endangered lungless salamander. It is endemic to Texas, United States. It was first found in Barton Springs in Austin, but is now also known from other localities in the nearby Travis and Hays Counties. Barton Springs is located within Zilker Park which is situated in the Edwards Aquifer in Austin, Texas. Eliza Springs, located within Barton Springs, has one of the largest populations of Barton Springs salamanders.
The Texas Hill Country is a geographic region of Central and South Texas, forming the southeast part of the Edwards Plateau. Given its location, climate, terrain, and vegetation, the Hill Country can be considered the border between the American Southeast and Southwest. The region represents the very remote rural countryside of Central Texas, but also is home to growing suburban neighborhoods and affluent retirement communities.
The Edwards Plateau is a geographic region forming the crossroads of Central, South and West Texas, United States. It is named in honor of Haden Edwards. It is bounded by the Balcones Fault to the south and east; the Llano Uplift and the Llano Estacado to the north; and the Pecos River and Chihuahuan Desert to the west. San Angelo, Austin, San Antonio and Del Rio roughly outline the area. The plateau, especially its southeast portion, is also known as the Texas Hill Country.
The fountain darter is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is found in the headwaters of only two rivers in Texas, United States: the Comal River and the San Marcos River. It is generally smaller than 3 cm (1.2 in) long and feeds on small invertebrates. It is a federally listed endangered species of the United States and is also listed as endangered by the IUCN.
Barton Creek is a tributary that feeds the Colorado River as it flows through the Texas Hill Country. The creek passes through some of the more scenic areas in Greater Austin, surrounded in many parts by a greenbelt of protected lands that serves as a habitat for many indigenous species of flora and fauna. The creek passes through Barton Creek Greenbelt and is fed by Barton Springs.
The Meadows Center for Water and the Environment, formerly Aquarena Springs and later the Aquarena Center, is an educational center in San Marcos, Texas. It seeks to preserve the unique archeological and biological resources of Spring Lake.
The Edwards Aquifer is one of the most prolific artesian aquifers in the world. Located on the eastern edge of the Edwards Plateau in the U.S. state of Texas, it is the source of drinking water for two million people, and is the primary water supply for agriculture and industry in the aquifer's region. Additionally, the Edwards Aquifer feeds the Comal and San Marcos Springs, provides springflow for recreational and downstream uses in the Nueces, San Antonio, Guadalupe, and San Marcos river basins, and is home to several unique and endangered species.
The Texas blind salamander is a rare and endangered cave-dwelling troglobite amphibian native to San Marcos, Hays County, Texas, specifically the San Marcos Pool of the Edwards Aquifer. This species resembles the olm, another stygofaunal salamander from Europe. Unlike the olm, this amphibian's body is not as elongated, and also has less reduced digits on its limbs.
The San Marcos salamander is a small species of aquatic, lungless salamander native to the United States, endemic to Spring Lake and a small region of the headwaters of the San Marcos River near Aquarena Springs, in Hays County, Texas. It is one to two inches long, with a slender body and external gills, and is reddish-brown in color.
San Marcos Springs is the second largest natural cluster of springs in Texas. The springs are located in the city of San Marcos, Texas, about 30 miles (48 km) southwest of Austin and 46 miles (74 km) northeast of San Antonio.
The San Marcos gambusia is a likely extinct species of Gambusia from the family Poeciliidae that was found only in the San Marcos Springs of Central Texas. The fish has not been seen since 1983.
The Georgetown salamander, also known as the San Gabriel Springs salamander, is a species of salamander in the family Plethodontidae. It is endemic to springs in Williamson County, Texas, near Lake Georgetown. It inhabits freshwater springs and, possibly, caves. It is threatened by habitat loss. Many of the springs where this species formerly lived have been destroyed by development, including creation of Lake Georgetown. The specific name refers to the few remaining remnants of habitat for this species.
Stygobromus pecki, the Peck's cave amphipod, is a rare species of crustacean found in four cavern areas of southwestern Texas in the United States. It is a federally listed endangered species in the United States and is also listed as Endangered on the IUCN Red List. Because of the species' limited geographical distribution, not much information on S. pecki is known. As of April 2022, there is no available 5-year review, Species Status Assessment, or recovery plan for the species. However, the Edwards' Aquifer Habitat Conservation Program (EAHCP), with the support of the U.S. Fish and Wildlife Service (UFWS), has been attempting to further study and promote conservation of S. pecki.
Balcones Canyonlands is a national wildlife refuge located in the Texas Hill Country to the northwest of Lago Vista, Texas. The refuge was formed in 1992 to conserve habitat for two endangered songbirds, the golden-cheeked warbler and the black-capped vireo, and to preserve Texas Hill Country habitat for numerous other wildlife species. The refuge augments a similarly named preserve in Austin called the Balcones Canyonlands Preserve.
Zizania texana is a rare species of grass known by the common name Texas wild rice. It is endemic to Texas, where it is found only on the upper San Marcos River in Hays County. It is threatened by the loss and degradation of its habitat. It is a federally listed endangered species of the United States.
Heterelmis comalensis is a rare species of beetle known by the common name Comal Springs riffle beetle. It is endemic to Texas in the United States, where it occurs in only two springs. It is a federally listed endangered species of the United States.
Clark Hubbs was an American ichthyologist who was professor of zoology at the University of Texas from 1963 until he accepted emeritus status in 1991. He was a leading figure in ichthyology in Texas, teaching many students who went on to be renowned in the field, was actively involved in many ichthyological societies and was an editor of scientific journals. Hubbs was also an environmental activist, fighting to conserve freshwater ecosystems.
