The U.S. Fish and Wildlife Service says Laguna Atascosa National Wildlife Refuge is open 365 days a year from sunrise to sunset, and that its visitor center is open Tuesday to Friday from 8:00 a.m. to 3:00 p.m.
The same page says the Bahia Grande unit of the refuge, off Highway 48 and Highway 100, is closed. That is the unit nearest the drive in from the mainland, so it is worth knowing before you plan a stop on the way over.
The refuge is worth the drive for birders in particular: the Service says it has more recorded species of birds than any other refuge in the National Wildlife Refuge System, at 417 species, and describes one 0.8-mile trail pair with bird viewing areas as a birder's must. It is also brushland where the endangered ocelot still hunts.
Hours and closures on a refuge change. The Service's own page is the authority and the link is below.
Sources: U.S. Fish and Wildlife Service, Laguna Atascosa National Wildlife Refuge — https://www.fws.gov/refuge/laguna-atascosa
