Lake Tahoe, famous for its clear, blue water, is one of America's greatest natural treasures. But for decades its water quality and clarity have been in decline. The U.S. Army Corps of Engineers is one of many agencies working to help "Keep Tahoe Blue". By restoring streams in the Tahoe watershed to their natural condition, water going into the lake will carry less sediment, helping maintain Tahoe's prized clarity. Soundbites from Sen. Dianne Feinstein, Roy Ranne, Katie Huff, Stan Hill. Produced by John Prettyman. Also available in high definition.