An on-going battle over proposed oil drilling in the Arctic National Wildlife Refuge took an ugly turn late last week when news surfaced that Interior Secretary Gale Norton had distorted government data about the impact of drilling on caribou populations. In a July letter to the Senate committee that had requested the data, Norton left out some statistics suggesting that caribou could be adversely affected, while including information that could be used to support drilling in the Arctic refuge. Furthermore, Norton inaccurately stated that caribou calving has been concentrated outside of the proposed drilling area for 11 of the last 18 years, when the opposite is true. Speaking Friday at a conference for environmental journalists held in Portland, Ore., Norton apologized for that error but did not address the other instances of skewed data.