This fiction book set in Butte Montana. A young boy makes amazing maps and illustrations and a teacher, I think, submits them to a national magazine and for years he makes these amazing illustrations and they don’t know it’s a kid. Eventually they give him an award and he doesn’t know how to get there (I think the teacher doesn’t want the secret revealed) so he hides on a train (this turns into kind of a magical time warp train ride) and goes to Washington DC. 
I think it must have been published prior to 2010? Around there or before.