Blue Buffalo Wilderness Trail Treats Grain-Free Dog Biscuits. Blue Buffalo Wilderness Trail Treats are grain-free dog biscuits. They are so tasty that the entire wolf pack would run for miles to get just one. The perfect crunchy treat for your meat-loving dog, Wilderness Trail treat biscuits are made with only the finest natural ingredients. Like all Blue Wilderness foods, Wilderness Trail Treat Biscuits are 100% grain-free so your dog can enjoy a high-protein treat without any of the grains that contain gluten.