The National Geological and Geophysical Data Preservation Program (NGGDPP) supports and fosters the archival of geological, geophysical, and engineering data, maps, samples, and other physical specimens by providing technical and financial assistance to state geological surveys and Department of Interior (DOI) bureaus. The NGGDPP supports a national cooperative network of geoscience materials and data repositories operated independently and guided by common standards, procedures, and protocols. Holdings of these repositories are accessible through the National Digital Catalog. Through the use of standards for metadata generation, data delivery and cataloging; leveraging methods and infrastructure established by efforts such as the U.S. Geoscience Information Network; and partnerships in data preservation and curation activities, the NGGDPP seeks to advance the sharing of geoscientific metadata and data to promote information discovery, access, and interoperability. The evolving aggregate of these repository holdings is providing an extensive source of geoscience data and materials to serve national needs.