This is a combined report from two BASIN (Biosphere-Atmosphere Stable Isotope Network) workshops: (1) September 16-17, 2004, Park City, Utah and (2) December 12, 2004, San Francisco, California. Stable isotope ratio analyses at natural abundance levels play a central role in understanding many ecosystem dynamics, patterns, and processes. These analyses are likely to play a central role in aquatic, atmospheric, and terrestrial components of the National Ecological Observatory Network (NEON) now in the planning stages. As a contribution toward development of NEON, scientists from across the nation interested in ecological applications of stable isotopes have met twice during Fall 2004 to discuss issues that would be of benefit to NEON and other national activities. This document summarizes our ongoing discussions. Here we describe a framework of rationale and plans for development of a network that provides infrastructure, monitoring capacity, research capacity, training, quality control, educational training, and outreach.