PNW-FIADB (Forest Inventory and Analysis Databases)

Notice: These PNW-FIA regional databases reflect the changes to cubic-foot volume, biomass, and carbon that were implemented in the national FIADB 1.9.1 release of September 29, 2023, which included the National Scale Volume and Biomass (NSVB) release (see https://research.fs.usda.gov/programs/fia/nsvb). These new methodologies replace the regional and Component Ratio Methods (CRM) of calculating volume, biomass, and carbon that were used in prior years.

The PNW-FIA databases contain forest inventory data for four western states divided into two databases: one for California, Oregon, and Washington and one for Alaska. This division was necessary due to differences in inventory methods. Both databases are provided in the SQLite format. SQLite is a widely used, public domain relational database management system with a size limit that makes it possible to store all FIA data in one portable database. Please see the SQLite home page (link is external; disclaimer) for more information. SQLite databases can be opened, queried, and edited using programs such as DB Browser for SQLite (link is external; disclaimer).

Note: In previous years, the PNW FIA program provided a Microsoft Access version of the databases in addition to the SQLite format. In 2023, the decision was made to discontinue the Access version due to challenges in developing and maintaining it. If Microsoft Access is needed, use the External Data tab within Access to create an ODBC database connection to import or link SQLite tables to an Access database.

California, Oregon, and Washington 

Download California, Oregon, and Washington - SQLite (Updated 03-10-2026; 1.1 GB) 

The California, Oregon, and Washington database contains data through the 2021 inventory year for California and through the 2022 inventory year for Oregon and Washington.

Alaska*

Download Alaska - SQLite (Updated 03-10-2026; 91.8 MB)

The Alaska database contains data through the 2021 inventory year.

Overview

The PNW-FIA databases combine data from the national FIADB for PNW states with many other regional PNW-only data columns and tables. They include down wood and understory vegetation for all our field plots, total stem volume, Scribner board foot volume, detailed information on disturbance, many calculated variables, coded columns to aid in grouping and organizing data and much more.

Status

For California, Oregon, Washington, and coastal Alaska, current estimates are based on the most recent 10 years of data, with the latest published year noted in the database download link.

Annual plot measurement has been underway since 2001. Plots are measured on a 10-year cycle with approximately 10% of plots being measured each year. When the 10-year cycle is complete re-measurement begins. The database includes the first measurement of a plot, when available. Because inventories started in different years, the set of remeasured plots differs among states as follows:

• California: first measurement cycle began in 2001, second measurement cycle began in 2011, third measurement cycle began in 2021.
• Oregon: first measurement cycle began in 2001, second measurement cycle began in 2011, third measurement cycle began in 2021.
• Washington: first measurement cycle began in 2002, second measurement cycle began in 2012, third measurement cycle began in 2022.
• Coastal Alaska: first measurement cycle began in 2004, second measurement cycle began in 2015.
• Interior Alaska: first measurement began in 2014 and is ongoing. Data have been published for the Tanana and Susitna-Copper inventory units.

*Note for Alaska data users: please read this document prior to any data analysis. FIA inventory unit boundaries do not follow Alaska’s borough and census area boundaries or ecoregions. Therefore, estimates and statistics based on these spatial features may be misleading. Interior Alaska is currently operating on a reduced sampling intensity and a periodic inventory design. This differs from the annualized inventory design utilized in coastal Alaska and the lower 48 states. More information about the interior Alaska inventory can be found here.

Additional Resources

Current data summaries for each state and related published reports using these inventory data can be found on our State Stats page.

Data for all states and territories in the U.S., including the PNW region, can also be accessed on the national FIA Data and Tools website. Raw data are available via the FIA Data Mart and table generator tools such as EVALIDator provide a user-friendly interface for producing quick, customizable data summaries. The national FIADB User Guide  provides comprehensive information on all fields in the database and is a good place to start when using the data.

The California, Oregon, Washington, and coastal Alaska inventories shifted from a periodic to an annual inventory design starting in 2001. Periodic inventories in these units sampled primarily timberland plots outside of national forests and most reserved areas, in a single state within a 2- or 3-year window. Typically, re-assessments occurred every ten years. Data from the periodic inventories for these units are available for download as the PNW-IDB Periodic Inventory Database.

Please contact us with any questions or concerns.