Bark Ranger

Border collie Gracie is on real-life paw patrol, helping to keep Glacier National Park safe for visitors and wildlife alike.

- BY MARY KATE FRANK

Picture this: It's a beautiful winter morning in Montana's Glacier National Park. Visitors admire a group of bighorn sheep grazing on a hillside. Eager to get the perfect photo, they inch closer to the herd. Maybe too close. The sheep weigh almost 300 pounds and are equipped with massive curled horns. They can get ornery when they feel threatened- say, if a selfie-seeking tourist invades their personal space.

Enter Gracie, an 11-year-old border collie, affectionately known as the park's "bark ranger." She approaches the sheep, lowers her head and crouches down to the ground, slowly creeping closer. Within moments, the herd retreats to a safer distance. Park ranger Mark Biel, Gracie's owner, rewards her with a piece of mozzarella string cheese, her favorite treat.