[2][8] One of the most well-known locations along the trail system is the Aransas National Wildlife Refuge, which holds the winter home of the only natural flock of whooping cranes in the world.

[2][8] One of the most well-known locations along the trail system is the Aransas National Wildlife Refuge, which holds the winter home of the only natural flock of whooping cranes in the world.

[10] A 1991 American Birding Association (ABA) study by Roland Wauer showed that Texas was the top bird-watching destination in the United States for its members.

[11] In 1993 the Texas Parks and Wildlife Department began a $1.5 million project to develop public and private resources to utilize as bird sanctuaries and observation sites.

The goal was both to encourage environmental protection and to establish a tourism network that would benefit businesses throughout the Texas Gulf Coast region catering to ecotourists.

[13] Events such as the state's Great Texas Birding Classic continue to build interest in the trails among nature lovers.

With annual rainfall averages ranging from about 20 to 58 inches (510 to 1,470 mm), this is a nearly level, drained plain dissected by streams and rivers flowing into estuaries and marshes.

The Piney Woods area features groves of pine and other hardwood trees such as oak, magnolia, and American Sweet Gum (Liquidambar styraciflua).

[19] The areas around Zapata and Laredo, which though significantly inland are considered part of the "coastal" trail system, feature a semi-arid climate as they lie near the eastern edge of the Chihuahuan Desert.

[26] In the Central Coast, the northern cottonmouth (Agkistrodon piscivorus) snake is prominent, not to mention dolphins and other marine mammals along the Gulf.

[28][29] Within each section, there are 43 "loops," hiking and driving trails containing specific birding sites ranging from parks and observatories to nature preserves and wildlife refuges.

[12] Along the coast near Port Arthur one can find pelicans, cormorants, horned grebes, orioles, Cape May warblers, and laughing gulls.

[34] The Piney Woods area of the Upper Coast section is home to species such as red-cockaded woodpeckers, bald eagles, Bachman's sparrows, the great crested flycatcher, the pine warbler, the red-shouldered hawk, and the barred owl among many others.

The Corpus Christi area features groove-billed anis, olive sparrows, long-billed thrashers, Couch's kingbirds, black skimmers, and black-crowned night herons.

South Padre Island and the Laguna Madre areas feature magnificent frigatebirds, bridled terns, and Cory's shearwater.

Annual nature festivals are held in Rockport, Port Aransas, McAllen, Galveston, Harlingen, and Mission attracting large numbers of visitors each year.