Former Colorado attorney general-turned-Interior Secretary Gale Norton is leaving the Bush White House, after more than five years as a member of the president's Cabinet.
Norton informed Bush of her decision in a letter Friday, saying her resignation will take effect at the end of March.
She leaves as her agency deals with a lobbying scandal over Indian gaming licenses, but told Bush only that it's time for her to catch her breath and set her sights on new goals in the private sector.
Norton was the first female Interior secretary of the U.S., and one of Bush's most controversial nominees because of her previous work for mining and logging interests.
She was one of the architects of Bush's energy policy, and eased regulations to speed approval of drilling permits, especially in New Mexico, Colorado and Wyoming's Powder River Basin.
Norton turns 52 Saturday.
She says she and her husband "hope to end up closer to the mountains we love in the West."