National Treasure: A Gates Family Mystery Westward Bound

Matthew Gates's older brother Thomas is convinced a treasure lies hidden with someone or something named Charlotte. But Matthew wants treasure that is more accesible. So, when in 1848, the first rumors of gold in California start spreading, Matthew eagerly leaves his family behind and goes West to seek his fame and fortune.  A year later, Matthew is part of the original Forty-Niners, with a claim and no money--yet. But then he overhears a fellow miner discussing odd glyphs found in his mine and Matthew's family instincts kick in. He sets out to see if the glyphs lead to something bigger than all the gold in California and in the process stumbles upon a group of Forty-Niners who will stop at nothing to claim a fortune.
Set during some of the most important moments in American history, the Gates Family Mysteries follow the ancestors of Benjamin Franklin Gates (immortalized by Nicholas Cage) as they search for treasure and strive to clear their family name.