Born in La Push, Washington
Leah is the daughter of Harry and Sue Clearwater, and she is the older sister of Seth Clearwater. In high school, Leah dated Sam Uley for nearly two years. When Sam imprints on her cousin, Emily Young, he breaks up with Leah. He doesn't want to hurt her, but imprinting is not by choice. Leah trusts her cousin to reject Sam, and she does for awhile. However, the two eventually spend more time together and become engaged. Leah is outraged!
Oblivious to her changing body, Leah becomes angry over the smallest things. When she argues with her mother about her mood swings, Leah explodes and phases into a wolf for the first time. Shocked that his daughter has shape-shifted in lieu of his son, Harry Clearwater has a fatal heart attack. When Seth witnesses his father's death, he phases as well. (In the movie "New Moon", Harry dies from a heart attack because of the vampire, Victoria.)
Still suffering from her break-up with Sam and her betrayal by her cousin, Leah is in even more pain now, as she blames herself for her father's death. So when Leah and Seth join Sam's pack, she constantly reminds Sam and the pack of her misery.
Although still angry, Leah eventually forgives Sam and Emily, as she understands now why Sam had to make the choice he did. However, being mentally connected to Sam through the pack is hard for Leah. Therefore, when the opportunity arises for her to leave his pack and join Jacob's, Leah takes advantage. Eventually, she becomes Jacob's Beta wolf.
Although she is the fastest in both packs, Leah hates being a wolf just as she hates vampires. Leah is very loyal to her friends, and she's extremely protective of her little brother. According to the Quileute tribe's history, Leah is the only female to ever phase.