Porter is a 20th-century American survivalist who, with his partner Butch, takes Chakotay and Torres prisoner after their shuttle crashes in the Arizona desert in Future's End, Part II.
Porter appears in the third-season episode Future's End, Part II, set in 1996. When Henry Starling's interference brings down the shuttlecraft carrying Chakotay and B'Elanna Torres, they wake tied up in the hideout of two armed anti-government militiamen.
Porter is the talker of the pair, full of theories about federal conspiracies. He takes the strange aircraft, the uniforms and Torres's forehead as proof that Washington is up to something sinister, and Chakotay's calm attempts to reason with him get nowhere.
The stand-off ends when Tuvok and the Doctor arrive. The Doctor, newly mobile thanks to Starling's 29th-century emitter, strolls through the gunfire unharmed, and the bewildered militiamen are quickly subdued.