ANCHORAGE, Alaska – A massive oil spill discovered earlier this month at Prudhoe Bay is the largest ever on Alaska's North Slope, officials said Friday. Between 201,000 and 267,000 gallons of crude leaked from a ruptured transit line onto the snow-covered tundra, according to an official estimate of the spill. That amount far surpasses the 38,000 gallons spilled in 2001, officials said. By comparison, the Exxon Valdez spilled 11 million gallons when it ran aground in Prince William Sound in 1989. “I can confirm it's the largest spill of crude oil on the North Slope that we have record of,”...