This research extends an on-going investigation of community-based environmental protection agreements that have been implemented for watersheds in the United States. The research uses a transaction cost framework to analyze the factors constraining and facilitating cooperation among the administrators, politicians, and interest groups that negotiate policy agreements cutting across many political jurisdictions. The project consolidates information from more than 2,000 watersheds, interviews a large number of stakeholders from a sample of those watersheds, and then uses case study methods to intensively study a handful of watersheds. This research provides an enhanced understanding of the ways in which cooperative agreements can be tailored for specific institutional settings and environmental domains. Building on previous and on-going research, the present research implements a design that makes it possible to track how the institutions for establishing community-based environmental protection agreements evolve over time and how stakeholders' strategies for involvement change accordingly. ©à ??%à ? ?¥©Ã? Ã??%/>/Â¥??` Â/?Â¥??¢ ¥©à ?/¥¥Ã?> _??Ã% ??%% ?à ?¢Ã? Â¥? ??Ã>Â¥?Â` ©?? ¢?Ã??Â?? Ã??>?_?? ?>Â??_/??> /ÂÂÃ?¥¢ Â?>/% ?Ã??¢??> ??Â¥??_â «Ã??Â??/Â¥??> ? ?â?%¥¢ ?¢ /???_?%?¢©Ã? ?` /??%`?>À ¥©à _??Ã% Â¥? / ?Ã??â Ã>Â¥/Â¥??à ¢/_?%à ? ?/¢Ã¢ />? Ã?/_?>?>À ©?? ?%?¢Ã%` ¥©à _??Ã% ?Ã??âÃ>¥¢ ¥©à ?Ã??¢??> ????⢠/>? ??Â¥??_â ¼©à ??Ã>Â¥?Â??/Â¥??> ? ?©/Â¥ Ã??>?_?? >Â??_/Â¥??> ?¢ _?¢¥ ?¢ÃÂ?% />? ??Ã???%à ¥? ?Ã??¢??> ?/?Â¥????/>¥¢ ?> Ã?/%?/Â¥?>À Ã>????>_Ã>Â¥/% ?©/>Àâ ??%% %Ã/? Â¥ ? _??à ÃÂÂÃ?Â¥??à ?>??????/Â¥??> ? Ã>????>_Ã>Â¥/% ?/%?â ?>Â¥? ???%?? ?Ã??¢??>¢