In mid-November, south-central Alaska was hit by freezing rain followed by subzero nights, a clear sign that the state's abnormally warm autumn was at an end. During frozen winter days, the Anchorage area's energy demand regularly skyrockets by more than 200 percent. To keep the heat and lights on in Alaska's most populated region, local utility companies primarily burn natural gas from the Cook Inlet, a 300-mile finger of water that stretches from the Gulf of Alaska to Anchorage. But for the past decade, gas production declined as energy developers in the inlet drilled fewer new wells and chose not to reinvest in their existing facilities. This winter, however, Alaska's energy woes have eased as nearly a dozen independent oil and gas companies are breathing new life into the inlet's energy extraction industry.