“The coordinates of a place are four-dimensional, not just three,” says Chris Engman, an artist who builds and photographs temporary edifices—stacked 55-gallon oil drums, split logs, wooden scaffolds, even a gravel heap—with time in mind. First there’s the time he spends assembling them, the solitary labor you don’t see in the final image. Then there’s the secondary process, the waiting, as the sun clocks overhead to assume a position in the sky that precisely reverses the angle in one shot, which he then captures in a second. But look closely at, say, a seemingly random pile of cinderblocks in the Nevada desert, and you’ll see that they, too, have been reversed. The diptych panels collected in his new show Dust to Dust often have such subtle multiples, a doubling of labor and image. Engman calls his unseen efforts “the manual version of Photoshop,” the careful schlepping of materials instead of the clicking of a mouse. But his photos only document the effects, not the sweat. And when his projects are over, they’re disassembled or allowed to decay, subject to the erosion of time. “Nothing lasts,” says Engman, “just like the mountains.” BRIAN MILLER

Thu., Nov. 18, 6 p.m.; Tuesdays-Saturdays, 10:30 a.m.-5 p.m.; Sat., Nov. 20, noon. Starts: Nov. 18. Continues through Dec. 24, 2010