What is the setting of "The Red Convertible"?

The story is set on the Chippewa reservation in North Dakota. The two protagonists, Lyman and his brother Henry, buy a red convertible which they take on a road trip. They end up in Alaska, where they spend most of their summer. At the end of the summer, the brothers return home, and Henry is drafted into the American army to fight in the Vietnam war.
Towards the end of the story the river on the reservation, called the Red River, becomes an important part of the setting. Henry, traumatized after his experiences in the war, jumps into the river and is carried away by the current.
The story's setting in time is, of course, very important too. Erdrich published the story in 1974, but the story itself is set in the late 1960s during the Vietnam war. This war heavily influences the story. Henry returns a broken man, as did so many men who fought in the Vietnam war.