Songfacts®:

• The woman in "Unknown Legend" is Neil Young's wife (at the time), Pegi Morton Young. The two met in 1974, while Morton was working as a waitress at a diner near Young's ranch.
  
  The song talks about a waitress, now mother of two, who had once lived a life of travel and restlessness. The chorus harks back to her years of riding a Harley Davidson through the desert, with its chrome and steel "Collidin' with the very air she breathes." The song sounds both triumphant and sad. It laments the woman's situation ("Now she's dressin' two kids, lookin' for a magic kiss") while celebrating the wild rambling imagery of her past, all while sweetly observing her graceful movements across the diner floor.
• Young and Morton were married from 1978 to 2014. They had two children together, Ben and Amber, both born with cerebral palsy, which inspired Neil and Pegi to start a non-profit called the Bridge School.
• A historically interesting note is that "Unknown Legend," which is an ode to Pegi, appeared on an entire album Young had made about keeping marriage alive. "This album here [Harvest Moon], it's about making things last, how to keep that interest, how to keep the fire burning," Young told New Musical Express in 1992. "Never get bored with the fact that you've been with someone for a long time, it's a good thing, not a bad thing. Relationships should enrichen with age, that kind of thing."
  
  The marriage did indeed enrichen for over a decade after the song's release, but then collapsed. In that same New Musical Express piece, writer Gavin Martin prophetically wrote, "No marriages are easy, rock 'n' roll relationships are particularly fraught. Placid and healing on the surface, Harvest Moon doesn't try to deny the troubles and heartbreak beneath."
• Pegi spoke a lot about her divorce from Young on her album Raw. It's an interesting dynamic - the "Unknown Legend" herself singing candidly about the harsher aspects of being married to the man who once immortalized her in song.
• Young released another song about Pegi in 1981: "T-Bone." Both songs recall how they met when she was working at a restaurant.