UNAVCO has operated a GPS data archive since 1992. The Archive has experienced tremendous growth in the past year, due in large part to addition of the PBO and Nucleus project holdings. The Archive currently holds 2.5 terabytes (compressed) of GPS data and data products, compared to less than one terabyte of holdings one year ago. Growth rates in excess of one terabyte per year can be expected for the duration of the PBO project. Data files are received and archived regularly from 850 permanent stations. The automated archiving system for permanent station data underwent a complete overhaul during 2005 with an eye towards improving overall scalability. Multiple parallel pipelines for handling incoming data now allow far more rapid throughput for archive injection, RINEXing, QC and ftp availability. Additional capability for handling archiving of high rate incoming data was implemented during 2005 in support of PBO archiving requirements. Search and access mechanisms for permanent station data via the Archive web pages are currently being upgraded Campaigns are received and archived at a rate of about 50 per year, with over 600 campaigns currently held. Campaigns make up approximately 12% of the holdings in the UNAVCO Archive and are a unique resource for the community. For the past several years, scanning of campaign log sheets and other documentation has been a regular part of archiving of incoming campaigns. Documentation for campaigns archived prior to 2003 is scanned as time permits. Search and access mechanisms via the Archive web pages for campaign data are currently being upgraded. In particular, new, simpler mechanisms for pickup of anonymously available data are being implemented. In support of PBO, the UNAVCO Facility Archive recently implemented mirroring of PBO holdings to an ftp server hosted at the IRIS Data Management Center in Seattle, Washington (ftp://data-out2.unavco.org). This ftp server is available as a second location for accessing all PBO and Nucleus data, allowing for continued data availability even in the event of a failure of the ftp system in Boulder. Plans for expansion of the IRIS-hosted secondary PBO archive in accordance with the PBO Data Management plan include implementation of the capability to fully replace the Boulder archiving functions for PBO data and products should these systems fail in Boulder.