Substance use-related problems continue to be a national public health crisis despite years of prevention efforts. Community anti-drug coalitions are well positioned to address substance use at local levels. Coalitions often rely on their members to connect to resources they need to address community issues and plan for sustainability over time. Such capacity building occurs through voluntary cooperation among members, making it essential to understand the role network connections play. This study sought to determine whether structural characteristics of coalitions’ resource sharing networks impact members’ perceptions of community improvement and coalition sustainability. Surveys at two timepoints collected data from 68 coalitions in Pennsylvania and Missouri on members’ connections or ties to share information, personnel, money, or other types of collaboration. Analyses examined how coalition-level measurements of sectoral diversity, density, and resource sharing centralization, respectively, were associated with members’ perceptions of community improvement, sustainability planning, and coalition sustainability. Sectoral diversity and centralization were unrelated to study outcomes. Density was also unrelated with perceived community improvement and sustainability planning. However, two facets of cooperative density were positively associated with perceived coalition sustainability: the density of ties to share information and the density of multiple types of collaborative ties. This study suggests that both information and other collaborative ties foster perceived coalition sustainability, although not community improvement.