Thomas Haden Church narrates a look at the vast Big Bend National Park on the Texas border on “Nature” (PBS, 8 p.m., check local listings). “while it is one of the least visited national parks in the U.S. because of its remote location,” cinematographer Skip Hobie says, “it is actually one of the highest rates of return visitation, because once you have been there, you fall in love.” The episode covers its hummingbirds, bighorn sheep, bats, and the recent return of the black bear.
Robin Roberts hosts the Black History Month special “Tuskegee Airman: Legacy of Courage” (History, 8 p.m.), honoring pilots that include her father, Col. Lawrence Roberts.
The competition among workers and laborers, “Tough as Nails” (CBS, 8 p.m.), returns for its second season.
The Impeachment of Donald Trump (CSPAN, CNN, PBS, MSNBC, noon) continues, providing fodder for shows like “Full Frontal with Samantha Bee” (TBS, 10:30 p.m.).
“Riverdale” (CW, 8 p.m.) makes a huge seven year jump, so that the actors now look a little closer to the age they are supposed to be than they did playing high school students derived from the comics.
A new “NOVA” (PBS, 9 p.m., check local listings) looks at the development of environmentally-friendly plastics.