Long-term environmental research and observation networks, including the Long-Term Ecological Research (LTER) network, Long-Term Agroecosystem Research Network, Critical Zone Observatory (CZO), Global Lake Ecological Observatory Network (GLEON), and National Ecological Observatory Network (NEON), are providing an important underpinning to the ecological data revolution. These collaborative efforts often provide economies of scale that yield data sets spanning larger spatial scales and/or longer time-scales than could be collected by a single investigator. Many of these networks both provide and actively advocate for open and FAIR (Findable, Accessible, Interoperable, and Reusable) data. Such networks also provide a hub for communities of expertise to set standards for experimental and science designs, data collection, data management, and synthesis. Continued investment in large-scale and long-term programs provides the opportunity for inter-generational cooperation and continuity in data-streams that improve conceptual and numerical modeling efforts and yield higher impact science, but also many challenges. The variety of networks that are currently operating provide diversity in both publicly available data as well as approaches to solving the many challenges that come with managing complex networks of infrastructure and heterogeneous data streams. The goal of this session is to highlight grand challenges in ecology and the environmental sciences that can be addressed as we de-silo and integrate across networks. The speakers will address questions such as: Where are opportunities for cross-program collaboration and synthesis? What are barriers to cross-network collaboration? Where are common areas of need? What are common challenges that might have common solutions? What are some success stories? What are important initiatives that the community should know about? How can early career researchers get involved, provide input, use data, and participate in synthesis? What resources are available for researchers who want to tap into network infrastructure or data for synthesis work? The speakers will provide a variety of perspectives, representing some of the different ways in which scientists interface with different networks (e.g., network leadership, advisory committee, investigator, data manager, data end user, facilitator of network synthesis science). We hope this symposium will bring scientists from different networks, or those who wish to learn about such networks, together to listen to each other’s goals and challenges and find opportunities to for cross-network synergies.