Rhoda is on a long hike in the north woods with her aunt and uncle. While her relatives watch for wildlife, Rhoda's only goal is to find rocks. She fills her backpack with treasures of all shapes and patterns—hearts, stripes, and sparkles—making it heavier and heavier as they move through forests and streams. By the final day at the "Big Lake," her pack is too heavy to lift. Unable to carry them all home, Rhoda finds a clever solution: she stacks her forest and river rocks into balanced towers by the water, keeping only a few of her most precious favorites for her windowsill.