DEAN: What do you want?
RORY: Do you remember that girl Butterfly who lived in a tree for a year? I can officially attest that she was nuts.
Rory refers to Julia “Butterfly” Hill (born 1974), environmental activist. She is best known for having lived in a 180 foot tall, roughly 1500-year-old California redwood tree for slightly more than two years between 1997 and 1999. Hill lived in the tree, affectionately known as Luna, to prevent loggers from cutting it down. She is the author of the 2000 book The Legacy of Luna and co-author of One Makes the Difference. Her story has often been alluded to in popular music and culture.
Rory climbs a tree in order to reach Dean while he’s in his bedroom, in the same way she climbed a tree to talk to Lane when she was grounded. There is a slight feeling of Romeo and Juliet, with Rory taking Romeo’s role in talking to Juliet while she’s on her bedroom balcony.
The Annotated Gilmore Girls 