Jack, a stocky cattle dog with a graying face that blends into his blue, mottled coat, struts down the mossy trails of western Oregon with purpose. On or off leash, his focus is keenly attuned to his handler and partner, Collette Yee. And it’s not just the yellow dog toy in her hands that draws his attention. The two can read each other’s most subtle cues, and have an unbreakable bond built on years of expert training, mutual reliance, and time together in the field. For the past six years,…