My son, 8 years old/4th grade, is getting ready to finish the Heroes of Olympus series of books (has gone through Harry Potter series and Percy Jackson series).

In order to "broaden" the types of books he reads (he wants to start the Fablehaven series next) I would sort of like to throw a 'Western' or 'Historical Fiction' book in there for him to try.

So, are there any fiction books about 'the Wild West' or 'Historical Fiction' books you can recommend that would be on his reading level with appropriate content?

Thank you very much for any and all helpful advice!

TripleB