Many of the most important scientific and management questions require some sort of regionalization. Problems are too widespread and numerous to be treated on a site by site basis and ecosystems are too variable to be treated the same way nationwide. The paper demonstrates the use of a regional framework for determining chemical and biological goals for surface waters. In four case studies, an eco-region map drawn from landscape characteristics was used to stratify the naturally occurring variance in water quality and biological communities. An ecoregion framework helps apply sound ecological theory to setting goals for entire states or regions of the country. Such a framework is an important bridge between site-specific and national approaches. When combined with appropriate statistical design, the ecoregional approach can provide precise expectations about large numbers of water bodies that would not be possible from traditional site-specific research or river basin surveys. (Copyright (c) April 1988, Journal Water Pollution Control Federation.)