*Is photography an art form? Yes, as we can see from two exhibits at the Rockwell Museum.

*Some people might not be sure. After all, with a painting or a sculpture you have to start with a blank canvas, or a chunk of rock, and create something out of nothing. While with photography, you just point at what’s already there, and snap the lever – right?

*Unsurprisingly, there’s a good deal more to it than that, as John Doddato and Peter McBride show us. Even without getting into the technical stuff, selecting the right sight TO photograph… then stalking that fugitive blend of subject, angle, shadow, and light… sometimes takes hours of waiting for two or three seconds of opportunity.

*A staggering example is McBride’s photo taken in the region of the headwaters of the Colorado River. As I approached from across the room, it puzzled me. It looked almost like silhouette figures on a southwestern vase – though if that’s what it was, it was a contemporary piece. Even standing before it, I still didn’t get it… then finally my mind’s eye clicked everything into place. What had seemed like the elongated silhouettes of horses were actually the SHADOWS of horses, as seen from directly overhead, at an altitude of 600 feet.

*With help from his pilot father, McBride had crystallized a single instant from an incredible viewpoint, creating an outstanding image of one man and 21 horses in a split-rail corral.

*This huge color photo is part of the exhibition “The Colorado River: Flowing Through Conflict” in the Rockwell’s Temporary Exhibition Gallery. The huge Colorado is so heavily used that it actually peters out into sand long before it reaches the sea. McBride and his collaborator Jonathan Waterman demonstrated that fact after following the flow for hundreds of miles, and then walking 90 miles to salt water along the theoretical bed of America’s seventh-largest river.

*The journey and the photos are a celebration of the river. A gorgeous view of two anglers fishing in the Roaring Fork tributary captivates even non-fishermen. (Study the two men in the river – see how the blur of their movements adds to the scene.)

*A scene of Marble Canyon in the upper Grand Canyon turns our world upside down. The walls of the canyon rise straight on either side, and in between, down at the floor of the canyon is – the sky, white clouds captured perfectly in reflected blue.

*But the photos are also a disturbing record of how we use and misuse the mighty stream. A Las Vegas swimming pool is one of thousands of pools and water features that gulp water from the river and throw it off as evaporation, largely just for the sake of spectacle. An aerial view of Phoenix shows a mighty metropolis, complete with palm trees, country clubs, and water features, in land that’s naturally desert. Westerners often like to vaunt themselves as self-reliant rugged individualists, but in fact their life is made possible only by gigantic government projects, and massive consumption of other people’s water – in the case of Phoenix, one-third of it from the distant Colorado, another third from that river’s tributaries, and a third from nearby underground aquifers.

*For all that, residents are following an ancient tradition. Ancient Hohokam people created 1200 miles of canals to support themselves on the same site.

*While the McBride exhibit shines in eye-squinting color, John Doddato’s “In Pursuit of the American Landscape” show in the Members Gallery is understated grayscale using an old silver-gelatin process. Doddato was born in Sayre and lived in Big Flats, but he takes us on a photo journey of the American West.

*Some of the images here, such as the mitten rocks in Monument Valley, and the dunes at sunrise in Death Valley, are views of well-known, well-traveled scenes. But here also is a streamside scene of Castle Creek outside Aspen, centered on a dead and fallen spruce. Another photo records a grove of Aspens, quietly glowing.

*I find myself repeatedly gazing at the ancient Flame House under the overhang on Cedar Mesa. The large blocks of which the structure is built are impressive, but what captivates me are the four utterly black doorways. In one sense, they lead to that empty and long-lost world of the original inhabitants. In another sense, they open to every possibility that imagination might devise.

*I keep on saying this, but I’ve always got good reasons: go to the Rockwell Museum. The McBride show runs through February 7, and Doddato through March 10.