Clearly, though, both the BLM and Barrett are most skittish over the allegations of dust damage to the canyon's rock art. When I spoke to BLM managers and Barrett executives in the spring and summer, they repeated the same talking point: Silver's findings were inconclusive. In a May editorial published in a local paper, a Barrett official even cited her study to defend its use of magnesium chloride, which it had applied again that month.

Despite her role in the BLM's shenanigans, Silver obviously cares deeply about the rock art. That's evident in her comments in an early draft of her study: "During the public comment period, some years ago, several conservation scientists and conservators (including the author of this report), raised objections to the use of magnesium chloride for dust abatement in Nine Mile Canyon, because eventually some magnesium chloride will escape the road and be deposited in rock art. The potential for damage is very great, and remediation would be very difficult." Those comments do not appear in the published study.

Silver's recommendation in the next (and concluding) paragraph on how to solve the problem never saw the light of day, either: "Therefore, another road surfacing must be developed and implemented as soon as possible in proximity to all rock art panels. A very promising road surface system identified by the BLM is asphalt chunks that can be spread on the road and then packed in place. -- It is absolutely critical that this -- or some other system -- be employed as soon as possible to arrest the development of dust near the rock art sites."

Notably, this solution was never mentioned in the BLM's draft EIS of the Barrett proposal. As this story went to press, the agency was testing six different types of dust control along Nine Mile road involving the use of enzymes. Whether or not enzymes would be any less harmful to rock art panels than magnesium chloride is not known, because no studies on their impacts have been done.

The company could utilize existing roads that circumvent Nine Mile Canyon altogether. Environmentalists and archaeologists have repeatedly suggested this, but the company insists that the cost and operational constraints are prohibitive. The BLM, for its part, has never seriously considered it as an alternative.

Several groups, including the National Trust for Historic Preservation, which has listed Nine Mile Canyon as one of its nine most endangered places since 2004, are now paying for an independent engineering study to assess the viability of bypass roads.

A year after Silver conducted her study, conditions in Nine Mile Canyon remain unchanged. The road is crumbling under a steady parade of oil and gas trucks. Dust is still flying everywhere, eroding innumerable rock art panels, according to Miller and other archaeologists.

Final drafts of Silver's study and the BLM's evaluation of Barrett's drilling expansion are set to be released in the fall. At the most recent Utah BLM advisory council meeting in late June, Julie Howard assured attendees that, according to Silver's study, evidence of damage to Nine Mile Canyon's rock art from dust
and magnesium chloride was "inconclusive." 

Silver, for her part, seems to believe that her study was properly handled by both the BLM and the Bill Barrett Corporation. Until recently, she had not responded to repeated requests for comment on this story. Then, on Aug. 15, she sent me an e-mail stating, among other things: "The work that I am doing in Nine Mile Canyon -- with the full support of the BLM and BBC (Bill Barrett Corp.) -- is pure science and the chips are going to fall where they will."

Keith Kloor is a New York-based freelance writer and currently a Ted Scripps Fellow at the Center for Environmental Journalism, University of Colorado.