Yellowstone National Park bcramponFull size 1700 × 1133 pixels The Lamar River is a tributary of the Yellowstone River, approximately 40 miles long, in northwestern Wyoming in the United States Previous image Next image Leave a Reply Cancel replyYour email address will not be published. Required fields are marked *CommentName* Email* Website Save my name, email, and site URL in my browser for next time I post a comment. Δ