Julie of the Wolves hands us one of the most isolated characters in all of young adult fiction. For page after page, Miyax is literally the only human being within hundreds of miles. But even in her childhood she experiences isolation of a different sort. Her youth is by no means typical, as she's caught between two cultures and feels the pull of both of them. Because of this struggle, she can't quite fit in with her peers. Still, it's worth noting that when she's lost on the tundra, Miyax eventually makes the choice to be alone (for a while at least). And can you blame her? Practically everyone around her has hurt her or left her, so maybe she figures she'd be better off by herself.
Miyax chooses to isolate herself from society because everyone around her has failed her in one way or another. She can only be happy if she has only herself to rely on.
Miyax feels loneliest not on the tundra, when she's totally isolated, but among her family, whom she doesn't really love.