The San Pedro River, nestled in southeastern Arizona’s San Pedro Valley just north of the US-Mexico border, is one of the last undammed rivers in the Southwest and is considered a biodiversity hotspot. Lined with cattails, willows and cottonwoods, the marshy waterway shelters hundreds of diverse bird species, including many considered endangered and protected by federal law. The area is also home to the Fort Huachuca US Army base, which has been heralded as an example of the military’s efforts to become more environmentally conscientious due to its use of solar power and other “green” initiatives. Ten years ago, Fort Huachuca forged a plan to achieve “net-zero” by 2025. But today, that goal has been largely abandoned, and an expanding group of critics says the installation’s well-meaning conservation efforts are falling short, and the Army instead is posing a dire threat to a protected conservation zone as a result of the base’s rampant pumping of precious groundwater.