This document contains the proceedings of the Teton Summit Conference for Program Evaluation in Nonformal Environmental Education. The Summit was co-hosted by the Teton Science School (TSS) and The Ohio State University with the goal of improving efficacy of evaluation in environmental education. Contents include: (1) What Is Evaluation? (2) For Whom Is Evaluation Done? (3) Why Evaluate? (4) How Is Evaluation Done? (5) What Is and What Should Be? (6) The Politics of Evaluation (7) What Environmental Education Evaluation Can Look Like (8) P.A.R.K.S. as a Model; (9) Valuing Programs from an Economic Perspective: Cost Analysis in Environmental Education Evaluation; (10) Cost-Benefit and Cost-Effectiveness; (11) Other Factors When Considering Costs; (12) Should Environmental Education Program Evaluation Be Required? (13) Possibilities: Where Do We Go From Here? (14) Matching; (15) Evaluation and Research; (16) A Culture of Evaluation; and (17) Identifying the "It" in Evaluation. Appendices include a list of summit participants, materials from the summit, and a resource guide. (YDS)