Captain Walter Granger was the 22nd century commander of the Earth ship SS Mariposa.

In 2123, Granger led a colonization mission to the Ficus sector, with a mixed group of colonists ranging from Irish Neo-Transcendentalists to technology-saavy scientists.

Following the departure of the Neo-Transcendentalists on Bringloid V, the Mariposa crash-landed on a class M planet in a neighboring system, one-half light year from the Bringloid system. Only five individuals survived the crash, including Granger. He and his fellow survivors resorted to cloning in order for their colony to survive. (TNG: "Up The Long Ladder")