The Passage Assessment Database (PAD) geospatial file contains locations of known and potential barriers to salmonid migration in California streams with additional information about each record. The PAD is an ongoing map-based inventory of known and potential barriers to anadromous fish in California, compiled and maintained through a cooperative interagency agreement. The PAD compiles currently available fish passage information from many different sources, allows past and future barrier assessments to be standardized and stored in one place, and enables the analysis of cumulative effects of passage barriers in the context of overall watershed health. The database is set up to capture basic information about each potential barrier. It is designed to be flexible. As the database grows, other modules may be added to increase data detail and complexity. For the PAD to be useful as a restoration tool, the data within the PAD need to accurately depict the on-the ground reality of fish passage constraints. This requires the PAD to retrieve new barrier data and updates to existing sites and to have verified and vetted the information it receives. In 2013, new PAD data standards were designed to standardize this process, and refine the data in PAD making the data more robust. The standard is available online at: https://nrmsecure.dfg.ca.gov/FileHandler.ashx?DocumentID=78802. The new standards have been implemented for all new records since 2013. In the future, the new standards will be implemented for all existing records. If after reading the metadata, additional details about the PAD project are needed, please visit the CalFish website at www.calfish.org/PAD or refer to the PAD Methodology document at http://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=19037. To send comments about data issues, corrections, edits or to map a new barrier location not yet reported in the PAD please send an email to: Anne.Elston@wildlife.ca.gov. New as of 2020: This feature classes identifies species and life stages that may be blocked or otherwise not blocked by structures and sites. It identifies if it blocks upstream or downstream migration or both. Since one structure/site can be a barrier to more than one species or block a species and not another species there may be multiple records at each site. Please note that these are not duplicates and each site/structure has a unique PAD ID and Passage ID.Preferred citation: California Department of Fish and Wildlife, Passage Assessment Database, March 2021.