The library system at the University of Illinois, Urbana-Champaign, is large and consists of 42 separate units distributed across campus. The main library stacks and many of the units are filled well beyond capacity. To address the lack of shelf space, a new high-density storage facility will soon be constructed, and library staff members are currently selecting volumes to be moved as soon as the facility is completed. The first phase of the facility will hold approximately 1.8 million volumes. Most of the material being selected consists of lesser used serials and monographs. Much of the cataloging for the material currently consists of only brief (author/title access) Marc records (locally called Marcette records) making it difficult for patrons to discover and access the material. The Marc records of the selected material will be upgraded whenever possible. The library system is also migrating to a new online catalog this summer, and the new system allows shelf-list browsing, a capability lacking in the current system. This paper examines the various factors related to high-density storage, both negative and positive, that may impact the geoscience collections at University of Illinois, including the ability of patrons to discover and access materials.