Growing up on a cattle ranch in Colorado, Peter McBride knew the runoff from snowmelt that irrigated the ranch lands eventually emptied into the Colorado River, and he wondered how long it took the water of the Colorado to reach the Sea of Cortez. In 2009, on an assignment for National Geographic magazine, he found out that it no longer does. Because of drought and an increased demand for water by over 35 million people in western states, the Colorado River dries up after crossing the U.S.-Mexican border.

That discovery sparked a three-year project as Pete followed and photographed the length of the Colorado from its source in the Rocky Mountains. He produced a book, The Colorado River: Flowing Through Conflict, and an award-winning documentary film, Chasing Water, began making presentations and launched a traveling exhibit. He also ended up with an ongoing interest in the world’s water crises.

The more I traveled, the more I wanted to photograph the things I cared about or saw changing.

Concern for the environment has always driven Pete’s career. “I loved photography and loved traveling to remote parts of the world,” he says, “and the more I traveled, the more I wanted to photograph the things I cared about or saw changing. In Colorado we’re coming into our 13th year of drought, and to some degree my work has helped bring the issue and the conversation a little more to the forefront. Because water law and water discussions can get very wonky, to have a visual component that tells the story as well is really important.”His environmental work is not about assigning blame or pointing fingers. “Water is becoming an issue all over the world,” he says, “and we’re all users. If you’re having a salad in New York City in the winter, that salad was grown with Colorado River water; everything about the issue is interrelated. The beauty of photography is that it can show people what’s at stake, and it can get the conversation started.”

To capture his environmental images and commercial assignments, Pete travels light and relies on technology. “My go-to lens now is the 24-70mm NIKKOR; these days, most of my stuff is done with that lens.” He takes full advantage of his cameras’ high ISO capabilities to shoot low-light photography and will confidently push the ISO to achieve high shutter speeds for his aerial photos. He generally shoots with his cameras set to shutter priority. “I want to have more control of speed, and I can always boost the ISO if I need to increase depth of field.” Pete considers -1/3 EV his exposure compensation default because it provides greater color saturation. “And it’s a lot easier to lighten something later than darken it,” he adds.