This research approaches two interrelated aspects of life in an Andean community. First, I explore themanagement of communally owned herds, gardens and other common pool resources. Specifically, I address how successful collective action (CA) can be maintained in a social environment in which there are enticements to free ride, especially given the lack of punishment in the study community. Second, this research explores the dynamics ofagricultural, health advice, and food sharing networks. While the health benefits of inclusion in support networks have been documented around the world, we know much less about exactly how network membership is established andmaintained. Several theories have emerged to explain how CA can arise and persevere. Costly signaling theory predicts that differential participation in CA can convey information about qualities of fellow community members that are otherwise not easily observable, such as cooperative intent, knowledge, work ethic, skill and/or physical vitality. Conveying such information may enhance access to adaptive support networks. The research presented here proposes that one method for building an agricultural support network is by signaling one's worth as a network partner through participation in CA, which involves predominately agricultural tasks. Findings support my prediction that those who contribute more to CA have greater reputations as reliable, hard workers with regard to CA, and are considered the most respected, influential, and generous people in the community. My predictions that those with greater reputations have more social network partners, are relatively good reciprocal partners, and live in HHs that experienced better health were also supported. In a separate analysis, this research found that access to (and position in) health advice networks is associated with better health, and that those with knowledge about traditional medicines were among the most respected people in the community. This research adds to a growing literature that focuses on the role reputational incentives play in solving the tragedy of the commons, particularly in contexts where there is minimal punishment of free riders. This work also offers insights into how support networks form, focusing on the role of public contributions (collective action) in honestly signaling qualities that make one a valuable partner.