Crested Butte is a rapidly growing winter and summer recreation resort in southern Colorado that attracts outdoor enthusiasts for its downhill and cross-country skiing, fishing, hiking, bicycling, and other recreational activities. A consistently high quality water supply is extremely important because reports of an outbreak of waterborne disease would have dramatic economic repercussions for this mountain community. The existing treatment system needed to be upgraded, but climatic restrictions and cost considerations dictated that construction be completed quickly and cost effectively. The water district selected a package treatment plant to provide a traditional treatment train of flocculation, sedimentation, and filtration. The plant is easy to operate and has enabled the district to make efficient use of its two sources of supply. Includes tables, figures.