Rio Grande Valley is birders heaven. Bentsen-Rio Grande Valley State Park is one place where you may spot a plain chachalaca, green jay, great kiskadee or a least grebe. These rare birds are called "valley specialties" because they are found nowhere else in the United States. Cars are not allowed in the park. The park also has a tram and four nature trails ranging from 1/4 mile to 2 miles. It has a two-story high Hawk Observation Tower with a 210-foot-long handicapped access ramp, two observation decks and two handicapped accessible bird blinds. It has primitive camp sites.
If you go:
The park is open daily 7a.m. to 10p.m. The tram is free with $5 park admission and runs Thursday through Sunday, every hour starting at 9 a.m. and ending at 4 p.m.
Links:

2800 S. Bentsen Palm Drive
Mission, Texas 78572 USA
BentsenRGVSP@tpwd.texas.gov
Phone Numbers:
Park
+1 (956) 584-9156
+1 (956) 584-9156