We present a composition framework that facilitates novel musical mappings for large-scale distributed networks of environmental sensors. A library of C-externals called ChainFlow for the graphical programming language Max/MSP that provides an interface to real-time and historical data for large sensor deployments was designed and implemented. This library along with spatialized audio techniques were used to create immersive musical compositions which can be presented on their own or complemented by a graphical 3D virtual world. Musical works driven by a sensor network deployed in a wetland restoration project called Tidmarsh are presented as case studies in augmented presence through musical mapping.