* Jesse is the main character of Downriver. He is a 13-year-old boy from the suburbs of Portland, Oregon, USA, who is forced to move to a rural area in Oregon with his family.
* **River:
* River Jordan is a Native American boy who grows up in the same rural area as Jesse. He is a member of the Wishram tribe, and he has a deep understanding of the natural world.
* **Billy:
*Billy Bagwell is a friend of Jesse and River. He is a bit of a troublemaker, but he is also a loyal friend.
* **Mr. Bowles:
*Mr. Bowles is Jesse's teacher. He is a kind and patient man who encourages Jesse to learn and grow.
* Mrs. Bowles:
Mrs. Bowles is Mr. Bowles' wife. She is a gentle and caring woman who takes Jesse under her wing.
* Old Man Peterson:
Old Man Peterson is a local farmer who becomes a friend to Jesse. He teaches Jesse about farming and the natural world.
* The Stranger:
The Stranger is a mysterious man who appears in the novel. He is a powerful and dangerous man who threatens the lives of Jesse and his friends.
* **The Dog:
*The Dog is a stray dog that Jesse meets. He becomes Jesse's loyal companion, and he helps Jesse on his journey.