Leaf litter decomposition is a foundational process in stream ecosystems, contributing to carbon and nitrogen availability that supports aquatic food webs. In many headwater streams, terrestrial litter represents the primary energy source, linking riparian vegetation to aquatic consumers. Decomposition rates vary with leaf traits and environmental conditions, and this variation can influence resource availability for macroinvertebrates across stream habitats. Improving our understanding of these patterns will strengthen predictions of how environmental gradients and changing conditions affect nutrient supply, energy flow, and overall ecosystem functioning in freshwater environments. Quantifying litter breakdown is therefore an important step toward understanding how nutrients enter and move through stream food webs. This study measured leaf litter decomposition of three leaf types to characterize organic matter processing in streams across North America. Leaf packs of varying species were deployed in wadeable streams spanning environmental gradients within the National Ecological Observatory Network. Following in-stream incubation for one month, packs were retrieved and processed to determine percent AFDM loss as an indicator of decomposition. Preliminary results show variation in decomposition rates among litter types and stream environments, highlighting the influence of both local environmental conditions and litter characteristics on processing rates. These patterns suggest that both abiotic and biotic factors regulate how quickly litter is processed and how long nutrients remain available in stream ecosystems. Understanding spatial differences in decomposition is essential for predicting the supply of organic matter to macroinvertebrate communities and the structure and productivity of stream food webs. Since decomposition influences how long leaf litter resources persist in aquatic systems, these processes influence the timing and magnitude of energy transfer to higher trophic levels. These findings represent a first step toward linking litter processing with carbon and nitrogen transfer to aquatic consumers. Ongoing work on this project will integrate decomposition measurements with macroinvertebrate community data and stable isotope tracers to better understand the fate and drivers of carbon and nitrogen in stream food webs across diverse ecosystems and environmental contexts across North America.