The Vanishing Trail at Granite Creek

The trail is gone. So is the proof it ever existed. Emily and Quinn spot a fake QR marker at Granite Creek, then find that the public map no longer matches the ground. A missing survey bolt, a forgotten ranger spur, and a postcard from an unknown sender point to a secret someone wants erased before the Nature Lab's biggest outdoor event. To save the trail, the girls have to race from old records to rocky switchbacks and catch the person rewriting the map.