How often does one night of television offer two visits to the majestic Andes Mountains of South America? Documentaries on PBS and the Learning Channel accomplish the vicarious travel feat.
* "The New Explorers: Expedition Inspiration" (8 p.m.-9 p.m., MPT, Channels 22, 67) -- The expedition was to Mount Aconcagua in Argentina, at 22,834 feet the tallest peak in the Southern Hemisphere. The inspiration was provided by survivors of breast cancer, such as expedition leader Laura Evans and the other members of her party. They accomplished the climb in 1994 -- because they could. PBS.
* "High Sierra Search and Rescue" (8 p.m.-9 p.m., WBAL, Channel 11) -- His sister comes to visit Tooter (Robert Conrad) in this new episode. If she looks vaguely familiar, it's probably because the actress is Anne Lockhart, daughter of June Lockhart of "Lassie," "Lost in Space" and "Petticoat Junction" fame. NBC.
* "Northern Exposure" (9 p.m.-10 p.m., WJZ, Channel 13) -- Some fans believe the show expired when Dr. Fleischman (Rob Morrow) left in February. But the canceled series has three fresh episodes to go. Tonight, Ed (Darren E. Burrows) adopts a bear cub and Chris (John Corbett) learns how to control his dreams. CBS.
* "Law & Order" (10 p.m.-11 p.m., WBAL, Channel 11) -- Reminiscent of the 1994 incident in Riverside, Calif., a doctor (Tony Roberts) is investigated for issuing an illegal prescription that may have caused mysterious toxic fumes to emanate from a woman getting medical treatment (Elizabeth Ashley). NBC.
* "Science Frontiers: What's New Doc" (9 p.m.-10 p.m., the Learning Channel) -- Here we are in the Andes again, in a documentary that studies human reactions to high altitudes.
* "Great Balls of Fire" (9 p.m.-11:30 p.m., Lifetime) -- One of the relatively few good film biographies of a musical legend, the 1989 movie stars Dennis Quaid as piano-pounding, cousin-marrying Jerry Lee Lewis. Alec Baldwin shows up as the singer's cousin, evangelist Jimmy Swaggart, and Winona Ryder is his young wife.
* "The 20th Century: Crisis In Space" (10 p.m.-11 p.m., A&E; Network) -- Follow a minute-by-minute, factual account of the moon mission that provided the story for Ron Howard's hit new film, "Apollo 13," with host Mike Wallace.