High-elevation, headwater aquatic networks are crucial for water provisioning and ecosystem services in the western United States (U.S.) due to their capacity for water storage and recharge, streamflow generation, and specialized habitat. Because headwaters serve as large sources of water, nutrients, and solutes, headwater quality can have serious implications on quality and quantity of downstream waters. In this study, we focused on nitrogen (N) and phosphorus (P) concentrations and N:P stoichiometry to examine how nutrient dynamics change along a headwater network in the Rocky Mountains in Colorado, U.S. We used 27 years of data from a lake chain in the Niwot Ridge Long-Term Ecological Research site to understand changes in nutrient forms, stoichiometry, and synchrony along a glacier-fed lake-stream network. We found P was predominantly limiting across all sites based on multiple stoichiometric ratio metrics. TN:TP decreased along the network and was generally driven by decreases in N organic and inorganic forms. Streams tended to have higher N:P and nutrient concentrations than lakes or the Arikaree glacier outflow, though this pattern varied among nutrient forms and season. Lakes and streams served as nutrient sources or sinks with magnitudes varying along the network. However, some general patterns included lakes as sink for N and streams as a sink for P, while both produced autochthonous dissolved organic carbon (DOC). This study highlights the importance of freshwater network connectivity and the differential role of streams and lakes in modulating nutrients.