The workshop was held on June 17 - June 20, 2002 in Keystone, Colorado. The workshop was chaired by Patti Lynne Tyler (U.S. EPA Region 8) with support from David Klauder (U.S. EPA ORD/OSP) and Bobbye Smith, Regional Science Liaison (U.S. EPA Region 9). The workshop was organized into seven sessions: I. The Importance of Developing a Regional Critical Ecosystems Approach; II. An Ecosystem Approach to Assessment; Goals and Objectives, Endpoints and Measures; III. Assessing the Criticality of Places; IV. Issues with Assessment Data and Tools; V. Integration of Assessment Results to EPA Goals; VI. Perspectives from EPA Programs and Other Federal Agencies; VII. Send-off.