Shut your eyes and picture the great American West. What do you see? The boggling maze of the Grand Canyon, the sun streaming down on Yosemite, the pueblos at Canyon de Chelly, a moonrise over a sleeping New Mexican town, the mitten rock at Monument Valley, the sad profile of an Indian chief, a migrant mother with a worried face, a tornado in Kansas, a geyser in Wyoming, a gusher in Texas, a Marlboro Man on the range, Marilyn Monroe as a misfit, an open road, an endless sky, a surreal suburb, an empty parking lot?

You may be the victim of a great Western fantasy. Whatever image you chose, you can blame photography, which has done more than anything to construct our vision of the West, whether it's cowboys and Indians or parking lots and strip malls. If you have any doubt about this, check out "Into the Sunset: Photography's Image of the American West," an exhibition at MoMA.

As the show's curator, Eva Respini, notes in her catalog essay, photography and the West "came of age together" in the 1840s, and they grew up together. But did they lose their clear-eyed innocence together, too, and if so, when?