Colorado River (Texas) in the context of "Karankawa"

La Grange (/lə ˈɡreɪndʒ/ lə GRAYNJ) is a city and the county seat of Fayette County, Texas, United States, near the Colorado River. La Grange is in the center of the Texas-German belt. The population was 4,391 at the 2010 census, and in 2018 the estimated population was 4,632.

Austin (/ˈɔːstɪn/ AW-stin) is the capital city of the U.S. state of Texas. With a population of 961,855 at the 2020 census, it is the 13th-most populous city in the U.S., fifth-most populous city in Texas, and second-most populous U.S. state capital (after Phoenix, Arizona), while the Austin metro area with an estimated 2.55 million residents is the 25th-largest metropolitan area in the nation. Austin is the county seat and most populous city of Travis County, with portions extending into Hays and Williamson counties. Incorporated on December 27, 1839, it has been one of the fastest-growing large cities in the United States since 2010.

Located in Central Texas within the greater Texas Hill Country, it is home to numerous lakes, rivers, and waterways, including Lady Bird Lake and Lake Travis on the Colorado River, Barton Springs, McKinney Falls, and Lake Walter E. Long. Evidence of human activity in the region is estimated to date back at least 11,200 years ago, with early habitation by Clovis peoples and later by American Indian groups such as the Tonkawa. Austin and San Antonio are approximately 80 miles (129 km) apart, and both fall along the I-35 corridor. This combined metropolitan region of San Antonio–Austin has approximately 5 million people. Austin is the southernmost state capital in the contiguous United States and is considered a Gamma + level global city as categorized by the Globalization and World Cities Research Network.

The U.S. state of Texas has a series of estuaries along its coast on the Gulf of Mexico, most of them bounded by the Texas barrier islands. Estuaries are coastal bodies of water in which freshwater from rivers mixes with saltwater from the sea. Twenty-one drainage basins terminate along the Texas coastline, forming a chain of seven major and five minor estuaries: listed from southwest to northeast, these are the Rio Grande Estuary, Laguna Madre, the Nueces Estuary (Corpus Christi Bay), the Mission–Aransas Estuary (Aransas Bay), the Guadalupe Estuary (San Antonio Bay), the Colorado–Lavaca Estuary (Matagorda Bay), East Matagorda Bay, the San Bernard River and Cedar Lakes Estuary, the Brazos River Estuary, Christmas Bay, the Trinity–San Jacinto Estuary (Galveston Bay), and the Sabine–Neches Estuary (Sabine Lake). Each estuary is named for its one or two chief contributing rivers, excepting Laguna Madre, East Matagorda Bay, and Christmas Bay, which have no major river sources. The estuaries are also sometimes referred to by the names of their respective primary or central water bodies, though each also includes smaller secondary bays, inlets, or other marginal water bodies.

These water bodies include some of the largest and most ecologically productive coastal estuaries in the United States and contribute significantly to the ecological and economic resources of Texas. They are included in a number of national protected areas such as National Wildlife Refuges, a National Seashore, and a National Estuarine Research Reserve, as well as various state parks and other regional protected areas. The two most economically important (the Nueces and Trinity–San Jacinto Estuaries) have been designated by the United States Environmental Protection Agency as estuaries of national significance under the National Estuary Program. The Gulf Intracoastal Waterway runs through each of the major estuaries, linking Texas ports with others along the Gulf Coast of the United States.