Last summer, scientists at the National Oceanic and Atmospheric Administration observed dust blowing 85 miles from its source: Lake Abert and Summer Lake, two dried-up saline lakes in southern Oregon. This has happened before: Saline lakebeds are some of the West’s most significant sources of dust. California's Owens Lake is the nation's largest source of PM10, the tiny pollutants found in dust and smoke, while plumes blowing off the 800 square miles of the Great Salt Lake’s exposed bed have caused toxin-filled dust storms in Salt Lake City.