What are some places important to the story in The Absolutely True Diary of a Part-Time Indian by Sherman Alexie?

There are three major places of importance in the novel The Absolutely True Diary of a Part-Time Indian by Sherman Alexie. The first place that is important to understanding the story is the Rez, or the Indian reservation where the protagonist Junior and many of the main characters live. This is a place which is essential to the story, because it symbolizes the struggle of Junior's tribe but also of Native Americans in general, as they work to find a place to fit in in a country which has attempted to cast them aside to make it easier to ignore them. Junior, the main character, is very aware of this fact, and thus views the Rez as both a blessing and a curse. He sees it as a place which prevents him from finding a better life and a better opportunity for happiness. In Chapter 2, on page 13, Arnold says, "But we reservation Indians don't get to realize our dreams. We don't get those chances. Or choices. We're just poor. That's all we are."
However, he also sees the Rez as a place where he finds a lot of support and unconditional love, which are necessary ingredients for living a full life and growing into a well-rounded person capable of dealing with adversity. There, he sees a lot of bad things; he witnesses racism, violence, death, self-destruction, and the consequences of living in extreme poverty. He also sees people come together in beautiful and moving ways as a community, and this is something that Alexie wants us as the readers to take into account. To see both sides of the Rez is to understand the duality of the experience of being Native American in a country which can be cruel and unforgiving. 
The second important place is Junior's school on the Spokane Indian Reservation. This school is important because it is where Junior has two of the most profound experiences of his young life. The first is when he attempts to be positive about his studies and open his extremely old textbook, only to discover that it was the same textbook that his mother used when she was his age. Rather than be happy about this, Junior realizes the implications of being forced to use such an outdated textbook. He realizes that he is not getting the best education possible on the reservation and he feels very bitter about that. In Chapter 4, he says "My school and my tribe are so poor and sad that we have to study from the same dang books our parents studied from. That is absolutely the saddest thing in the world."
In a fit of anger, he chucks the book at his teacher, Mr. P, and breaks his nose. This is the second important thing which happens to him and influences his actions for the rest of the book. Because of the talk which occurs between himself and Mr. P about leaving the reservation and the opportunities that would be available to him if he did, he decides to attend Reardan High School, a white school which is located outside of the reservation: "Son," Mr. P said. "You're going to find more and more hope the farther and farther you walk away from this sad, sad, sad reservation" (43). 
Reardan is the third important place that Junior visits. This place is important to our understanding of the story because it is a place in which Junior learns to both appreciate the Rez and to realize how his own assumptions about the world were serving to hold him back more than just the assumptions of others about him. It is also a place where he feels "too Indian," just as the Rez is now a place where he feels too "white": "Traveling between Reardan and Wellpinit, between the little white town and the reservation, I always felt like a stranger. I was half Indian in one place and half white in the other" (143).