The Sauceda Mountains in south-central Arizona straddle the eastern section of the Barry M. Goldwater Bombing Range, which the public can explore with a permit. The Air Force trains air crews in fighter jets that twist and roar across the sky, practicing air-to-ground combat on its 1.7-million-acre range. Rare hikers, including my group, explored an otherwise untrammeled wilderness.

On the slopes of its low mountains, which cross arid basin and range country, saguaro and cholla cactus, mesquite bushes, and palo verde trees wreathe the desert floor. Hot summers attract moisture from both the Pacific Ocean and the Gulf of Mexico, which converges to create cloudbursts. The earth, as firm as concrete when dry, is formed by volcanic lava flows that have long since eroded down mountain slopes to form alluvial fans upon which plant life prospers.

On this night, facing the camera directly north, I exposed a piece of sheet film for seven hours as the full moon traversed the southern night sky, lending the saguaros a glowing radiance. These desert sentinels take one hundred years to mature. Most grow arms; however, a few, called “spears,” grow in drier soil and do not branch out.

Polaris – that small, bright semi-circle above the image’s center – pivots around the north point. The star’s position oscillates slightly during the year and, over thousands of years, swings in and out of alignment with true north. Though, to our eyes, and throughout our lives, it appears as a fixed presence, a guiding star, matching the same number of degrees above the horizon as the latitude from which we view it.