Westward Bound is book by Catherine Hapka in the "Gates Family Mystery Series" published in December 23, 2008 by Disney Press.
Synopsis[]
James Gates has heard the same story all his life. According to family legend, a treasure lies hidden with someone, or something, named Charlotte. For years, his father and eldest brother Thomas Gates have sought the elusive fortune, looking for clues that will bring them to the end of their quest. But James wants more immediate wealth.
When he discovers letter from his aunt that speak of fortune in the West, James sees his chance. But almost immediately, he runs into problems - in the form of a runaway aristocrat and a conspiracy-focused friend named Seamus. Soon, the trio find themselves bound together in a journey that will lead them to the most unlikely of treasures.