In Frank McNitt's biography of Richard Wetherill, the 19th-century explorer credited with the discovery of Cliff Palace, the great Ancestral Puebloan ruin in Colorado's Mesa Verde region, the author relates a story involving archaeologist Alfred V. Kidder.

Believing they had come across a previously unexcavated ruin, Kidder and his friend Jesse L. Nusbaum made a treacherous climb up a steep canyon wall to a narrow ledge. The men were excited by their successful climb and eager to explore the ruin. In McNitt's account of the incident, Kidder recalled, "We peered down through an opening in the rocks at our ruin. Right there before our eyes was an upended slab of stone. On it we read these words: What fools these mortals be. R. Wetherill."

Perhaps when Wetherill left this cryptic message, he was anticipating what would follow in the years to come, as more and more tourists would descend on Indian lands, cameras in hand, ready to stake their photographic claims. Perhaps his statement was aimed at himself, critical of his own folly.

Today, Mesa Verde National Park is a popular tourist destination. Photographer Zig Jackson captured images of tourists swarming Mesa Verde in a series of photographs titled What Fools These Mortals Be, in an obscure reference to Wetherill and perhaps as a reflection on a paradox. Tourism for places like Mesa Verde is a double-edged sword: it provides opportunities for education and research about past and present Native cultures, but the traffic can have devastating effects that sometimes extend to willful desecration. The walls in cave dwellings at Tsankawi in Bandelier National Monument, for example, feature modern graffiti alongside Ancestral Puebloan petroglyphs. For Jackson, the issue is one of insensitivity. "You wouldn't walk into a church and start taking photographs," he said in an interview with Pasatiempo, "but these are places many people hold to be sacred." According to the Web site for Mesa Verde National Park, 24 distinct indigenous groups claim cultural affiliation with the site.

Contemporary Pueblo people expect non-Natives to observe the proper etiquette when they attend Pueblo ceremonies and dances. Many of the rules visitors are asked to follow are just common sense — for instance, that visitors do not enter someone's home without being invited. The fact that such a rule exists suggests that uninvited guests in Pueblo homes have indeed been a problem. Responding to non-Natives' fascination with Indian artifacts (and with Indians as artifacts), Jackson created photographs that cast light on the phenomenon of Native people as a commodity. An image he shot in 1999 called Hotdogs, Corndogs, and Cold Drinks, Little Shell Pow-wow, N. Dakota shows people in traditional Indian dress alongside an array of food stands. The powwow dress makes an absurd contrast with the everyday sight of hot-dog stands. Jackson's biting sense of humor is even more prominent in a 1991 series titled Indian Photographing Tourist Photographing Indian.

In 2005, Jackson's work became the first by a contemporary Native photographer to be included in the collections of the Library of Congress, which also holds photographic work by Edward S. Curtis. Curtis has come under criticism in recent decades, because he staged shots, used props, misrepresented his Native subjects, and perpetuated the myth that Native peoples are a vanishing race. But Jackson mentioned that some of the Native students he taught at the Institute of American Indian Arts in Santa Fe said they would have known nothing about their ancestors were it not for the images and data collected by Curtis.

A member of the Mandan, Hidatsa, and Arikara tribes, Jackson was raised in North Dakota but now resides in Savannah, Georgia, where he teaches photography at the Savannah College of Art and Design.

Jackson's poignant series of road-sign images includes placards from reservations that stand out against stark, sparsely populated landscapes. Each sign informs travelers that they are entering a reservation, but other than the road that recedes into the distance, we see little else save power lines and empty fields. Jackson made his own sign, reading "Entering Zig's Indian Reservation," and took it to various locations throughout the United States to use as a prop in a series of self-portraits. In one of these shots, now in the collection of the Library of Congress, the photographer stands outside San Francisco's city hall. He looks stoic, wears a war bonnet, and stands next to the sign, which warns that the land is private property and that air traffic, hunting, photography, and New Agers are prohibited.

"The war bonnet is a source of honor and pride," Jackson said. "Not just anyone can make them. You have to be a person with medicine." Jackson's traditional Mandan bonnet was made by his father and passed down to him. Although the war bonnet works as a prop, it also represents Jackson's ancestry and serves to underscore his stated purpose behind his self-portraits: "I was reclaiming land."

Zig Jackson's work can be viewed at Andrew Smith Gallery, W. San Francisco St., 984-1234.