Motherless Mollie McCrea, whose father is in the Yukon, disguises herself as a boy named "Alaska" and hides on a steamer bound for that territory. Discovered, she is made to wash the decks until Phil Hadley, a lad of her age, pays her way, and they go together as pals to look for gold. When Phil becomes sick as they reach the cabin of an old timer, Mollie nurses Phil to health. They work the old timer's mine which proves to be rich, and he dies after telling Mollie that he is her father. Phil plans to go back to his sweetheart, but takes ill again and is again nursed to health by Mollie. After suffering when he finds out that his sweetheart has wed another, Phil happily discovers Molly's true sex when she disrobes to bathe. A minister marries them, and they return to civilization, wealthy from her father's mine.