Regional professional learning networks support school change by linking principals to others engaged in similar change work. While increasingly prevalent, little is known about the factors that contribute to the formation of ties between network members, or how knowledge moves across the network. Using social network analysis, this study examined the flow of information and advice in one such network and uncovered school leader and school characteristics correlated with increased tie strength, including being in the same state, having different years of network membership, and to a lesser extent, serving similar grade levels.