The United States Forest Service is temporarily prohibiting timber sales and logging on 11 million acres of national forests in the Sierra Nevada.The three-month suspension includes an area equal to 17,200 square miles that stretches from the Sequoia National Forest north of Los Angeles, along the mountains past Yosemite National Park and Lake Tahoe, to the Modoc National Forest on the Oregon border. The suspension will take effect on Dec. 11.