Jasper and the riddle of Riley's mine / Caroline Starr Rose.

Enhanced descriptions from Syndetics:

Hoping to strike it rich, two brothers escape an abusive father and set out on a treacherous journey to Alaska during the Klondike Gold Rush.

Desperate to get away from their drunkard of a father, eleven-year-old Jasper and his older brother Melvin often talk of running away, of heading north to Alaska to chase riches beyond their wildest dreams. The Klondike Gold Rush is calling, and Melvin has finally decided the time to go is now-even if that means leaving Jasper behind. But Jasper has other plans, and follows his brother aboard a steamer as a stowaway.

Onboard the ship, Jasper overhears a rumor about One-Eyed Riley, an old coot who's long since gone, but is said to have left clues to the location of his stake, which still has plenty of gold left. The first person to unravel the clues and find the mine can stake the claim and become filthy rich. Jasper is quick to catch gold fever and knows he and Melvin can find the mine-all they have to do is survive the rough Alaskan terrain, along with the steep competition from the unscrupulous and dangerous people they encounter along the way.

In an endearing, funny, pitch-perfect middle grade voice, Caroline Starr Rose tells another stellar historical adventure young readers will long remember.