Bentsen-Rio Grande Valley State Park is a 764-acre Texas state park south of Mission in the Rio Grande Valley and the headquarters of the World Birding Center’s nine-site regional network. It began on January 28, 1944, when members of the Bentsen family donated 586 acres as a nature habitat, creating the park’s core and linking its name to the family of Senator Lloyd Bentsen. Known especially for wildlife watching, it has recorded more than 325 bird species and over 250 butterfly species, with the adjacent National Butterfly Center adding to its importance. Since 2004, reduced vehicle access and discontinued RV camping have reinforced its focus on habitat and observation.