National Heritage Areas (NHAs) are an alternative and increasingly popularform of protected area management in the United States. NHAs seek tointegrate environmental objectives with community and economicobjectives at regional or landscape scales. NHA designations have increasedrapidly in the last 20 years, generating a substantial need for evaluativeinformation about (a) how NHAs work; (b) outcomes associated with theNHA process; and (c) the costs and benefits of investing public moneys intothe NHA approach. Qualitative evaluation studies recently conducted at
three NHAs have identified the importance of understanding networkstructure and function in the context of evaluating NHA managementeffectiveness. This article extends these case studies by examiningquantitative network data from each of the sites. The authors analyze thesedata using both a descriptive approach and a statistically more robustapproach known as exponential random graph modeling. Study findingsindicate the presence of transitive structures and the absence of three-cyclestructures in each of these networks. This suggests that these networks arerelatively ‘‘open,’’ which may be desirable, given the uncertainty of the environments in which they operate. These findings also suggest, at least at the sitesreported here, that the NHA approach may be an effective way to activate anddevelop networks of intersectoral organizational partners. Finally, this studydemonstrates the utility of using quantitative network analysis to better understand the effectiveness of protected area management models that rely onpartnership networks to achieve their intended outcomes.