26 native species and their habitats. It is a long-term plan that geographically encompasses the river and its corridor from Lake Mead downstream to the southerly U.S. and Mexico boundary. Three fishes, humpback, bonytail and razorback sucker, are federally listed endangered species. The MSCP also maintains conservation actions for the flannelmouth sucker, a native but unlisted species that resides in portions of the lower river. A large amount of data currently exists for these fishes, and substantial amounts of new information will be acquired for all of these species with the exception of the humpback. It is the responsibility of the MSCP to manage that information for the duration of the program. The Lake Mohave [Lower Colorado River (LCR)] Native Fish Database began under the direction of P. C. Marsh and the late W. L. Minckley, Arizona State University (ASU) in 1988. Beginning in 2009 responsibility for these data transferred from ASU to Marsh & Associates (M&A) under continued direction of P. C. Marsh. Tagging of native fishes in the LCR began in the late 1970’s with external tags being fixed to razorbacks in Lake Mohave. Over time, native fish tagging and the native fish data base have evolved to include numerous species, tag types, and geographic locations. Current tagging protocols include the use of both wire and Passive Integrated Transponder (PIT) tags throughout the LCR corridor. As scanned, PIT tags read either 7-, 9-, or 10- character alphanumeric sequences of any possible combinations of the digits 0 through 9 and letters A through F; HDX tags that are now in the database have 7 hexadecimal digits (0-9, A-F). Field data acquired by the Native Fish Work Group (NFWG) participants from bonytail, flannelmouth sucker, and repatriated (stocked) and wild adult razorback suckers are regularly generated and fish augmentation programs are expected to stock tens of thousands of native fish each year. All this data is incorporated into the native fish database, which is then accessible in a user friendly database. Database management, application and use consists of: (1) data entry from field notes and electronic stocking files for activities associated with the MSCP and its partners, (2) manipulations that organize or structure/ restructure the files, records, and their contained information, such as performance of sort routines, (3) manipulations that yield summary statistics for individuals and populations, such as days at large, change in length, and growth, (4) input to software that performs specific functions, such as mark-recapture analysis to estimate population size, (5) generation of summaries and information for reporting, and (6) capture history access via the internet. Database maintenance is labor intensive and demands meticulous control at all levels. Collection of sample data in the field is the first step to ensure completeness and accuracy of information. The recipient shall brief all field personnel in data acquisition methods and use of a standardized form/format to help towards keeping a complete record. Field data will be transmitted in original or duplicate copy to the recipient, where data are entered by keyboard into the database system. All incoming electronic files will be stored in their original condition on a computer, sorted by year and reservoir or river location, printed out, and then mated and stored with field data collection sheets. Each individual entry will be quality checked with text-to-speech software so that all database records are complete and correct relative to an original. If/when a discrepancy or other problem is detected, an attempt is to be made to make a correction. In some instances the original collector may be contacted to provide clarification or elaboration. Newer versions of the database will be regularly uploaded to a web server.