The National Oceanic and Atmospheric Administration (NOAA) collects and manages a wide range of environmental and geospatial data to fulfill its mission requirements--data that stretch from the surface of the sun to the core of the earth, and affect every aspect of society. With limited resources and enormous growth in data volumes, NOAA asked the National Academies for advice on how to archive and provide access to these data. This book offers preliminary principles and guidelines that NOAA and its partners can use to begin planning specific archiving strategies for the data streams they currently collect. For example, the book concludes that the decision to archive environmental or geospatial data should be driven by its current or future value to society, and that funding for environmental and geospatial measurements should include sufficient resources to archive and provide access to the data these efforts generate. The preliminary principles and guidelines proposed in this book will be refined and expanded to cover data access issues in a final book expected to be released in 2007.