Book excerpt: On the last day of second grade, twins Spencer and Maggie Parker come home from school to find a camper van in their driveway. And not just any camper; a magic camper that can transport them to every state in the continental US. This is perfect for Maggie, who loves geography and is a star student, and for Spencer, who’s been failing his geography quizzes and could use the real life extra credit. Together, the twins travel to a surprising new place--the rolling fields of Colorado! There they get suited up in cowboy gear, eat a hearty breakfast in the Mess Hall, and join a cattle drive. But when the group takes a moment to rest, the ranch's prized cow, Snowflake, is stolen by a band of rogue cowboys. The twins must discover how to work together in order to save Snowflake, and find their way home again.