The Bush administration has asked the United Nations to remove Yellowstone National Park from a list of endangered World Heritage sites. “Yellowstone is no longer in danger,” wrote the Interior Department’s Paul Hoffman in a letter to the World Heritage Committee. There’s just one snag: The park staff disagree with Hoffman, saying Yellowstone still faces the kinds of problems — threats to water quality, bison, and trout populations, among others — that put it on the endangered list in the first place, back in 1995. But in its recent report to the U.N. committee, the Bush administration diluted or deleted those problems, in a move critics say is emblematic of White House efforts to water down, sugarcoat, or deny environmental problems across the board. “Tinkering with scientific information, either striking it from reports or altering it, is becoming a pattern of behavior,” said former National Park Service Director Roger Kennedy.