Most scholars agree that strong local institutions represent a key ingredient of successful community governance of shared natural resources. There is less consensus about why such institutions emerge in the first place and why they often don’t emerge at all. Why do local users voluntarily assume the substantial costs of self-organized natural resource governance? Using a lab-in-the-field behavioral experiment that mimics forest resource dynamics, we observed the emergence of rules and norms over time among 16 forest user groups in Bolivia and Uganda. Our preliminary results show that conditions characterized by a combination of (a) saliency, (b) large increase or decrease in resource availability, and (c) leadership motivate the user groups to invest in creating and enforcing institutions. In addition, the emergence of institutions contributed to improved sustainability outcomes – which we measure by considering the simultaneous achievement of forest conservation, sustained income, and low intragroup economic inequality. Our (preliminary) findings imply that practitioners would benefit from considering the costs of local institutional development to forest users. We end the paper with a discussion of possible ways to incentivize the uptake of these governance institutions among community forest users.