Mark Buktenica Robert Collier Gary L. Larson 2003 Blue is the color of constancy, hence the term true blue. The unearthly blueness of Crater Lake reflects its pristine character and gives scientists a focal point for studying human impacts on aquatic environments over long periods of time. Scientists with the U.S. Geological Survey (USGS), National Park Service, and Oregon State University have systematically studied the lake for the last two decades. Long-term monitoring of this lake is a priority of Crater Lake National Park and will continue far into the future. application/pdf 10.3133/fs01803 en U.S. Geological Survey Crater Lake: blue through time reports