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Inventory Data

The Pacific Northwest Forest Inventory and Analysis (PNW-FIA) program measures and compiles data on plots in coastal Alaska, California, Hawaii, Oregon, Washington, and U.S.- affiliated Pacific Islands. Most data are available in Access databases and can be downloaded by clicking one of the links below. PNW data are combined with data from all states in the U.S. and stored in the national FIADB. Data for any state can be accessed on the national website (see links to national tools below). Please be aware that some documents may be very large.

The PNW-FIA Program shifted from a periodic to an annual inventory system in 2001. Periodic inventories 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 in the West. For the annual inventory in the Pacific Northwest all forested plots are now sampled, with one-tenth of the plots in any given state being visited annually. A full annual inventory cycle is complete in ten years.

PNW-FIADB: Pacific Northwest Annual Forest Inventory Database (AK, CA, OR, WA)

The PNW-FIADB is a Microsoft Access database with a user-friendly front end. It contains forest inventory data for 4 western states, many pre-built easy to run queries, database documentation, and field manuals. All of this is available at your fingertips -- by clicking one of the many buttons on the User Interface. This tool was created for users of PNW data – making it easy to summarize data, output results, create new queries, and work with the database tables directly. The PNW-FIADB is designed to simplify the process of working with the large and somewhat complex FIA database. Once the PNW-FIADB is loaded onto your computer – it becomes your database. It’s ready for you to analyze and incorporate into your own research project.

Click on the buttons below to review documentation or to download the database package from our server or request a CD.

Quick Overview

The PNW-FIADB combines data from the national FIADB for PNW states with many other regional PNW-only data columns and tables. It has down wood and understory vegetation for all of our field plots, total stem volume, Scribner volume, detailed information on disturbance, many calculated variables, coded columns to aid in grouping and organizing data, helpful reference tables to crosswalk codes to words, and has a special plot table that contains expansion factors (acres per plot), adjustment factors (a technical requirement of our inventory design), and other items that are needed to produce current estimates for any resource attribute of interest.

There are over 150 pre-built queries that you can run as-is by clicking one of the buttons on the Interface. More importantly, you can select a query, open it up for editing, customize it for your own needs, save it with your own query name, and later retrieve and run it whenever you need it.

Another component of the PNW-FIADB is a module that runs queries with an estimate of Standard Error for every cell in the summary table. This is a work in progress – many queries are available but more are being added over time. These queries can be instantly exported to Excel (via a button on the toolbar). A more formal report-writing product is being worked on so query results can be displayed in a well-formatted printable report.

All key documentation that is necessary to properly query and analyze the PNW inventory database is available at your fingertips, as well. Both the national and PNW User Guides (data dictionaries), User-Interface Guide, and field manuals are readily accessible by clicking buttons. Once clicked, a PDF of the document pops up – allowing you to search for and read details about the data.


The PNW-FIADB, currently available for download on this site, contains data from annual inventories for Alaska, California, Oregon & Washington. One complete inventory cycle is 10 years, with 10% of all plots measured in one year. Inventories started in different years as follows: CA and OR in 2001, WA in 2002, Coastal AK in 2004.

Current estimates are based on the most recent 10 years of data, with the latest published year noted in the database download link.

Remeasurement has been underway since 2001. 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: 10 year cycle, remeasurement began in 2011
  • Oregon: 10 year cycle, remeasurement began in 2011
  • Washington: 10 year cycle, remeasurement began in 2012
  • Coastal Alaska: Remeasurement began in 2015. Partial cycles collected in 2014 and 2016

Hawaii and Pacific Islands Database: Periodic Forest Inventory Database for the Islands

Forest Inventory and Analysis conducts resource inventories on Hawaii and the U.S. affiliated Pacific Islands of American Samoa, Guam, Palau, the Commonwealth of the Northern Mariana Islands (CNMI), the Federated States of Micronesia, and the Marshall Islands.

Data from these inventories are available in Microsoft Access databases. The applications contain a user-friendly front-end Interface with a series of push buttons and pop-up screens that simplify a variety of tasks.

Use the buttons below to download each database of interest:

Hawaii 2010-2015 inventory

Pacific Islands v.2017: American Samoa 2001 and 2012, Guam 2002 and 2013, Palau 2003 and 2014, CNMI, 2004 and 2015

Pacific Islands first inventory: American Samoa 2001, Guam 2002, Palau 2003, CNMI 2004, Federated States of Micronesia 2005, Marshall Islands 2008.

Quick Overview

Forest Inventory and Analysis conducts resource inventories on Hawaii and the U.S. affiliated Pacific Islands of American Samoa, Guam, Palau, the Northern Mariana Islands, the Federated States of Micronesia, and the Marshall Islands.

Data from these inventories (except Hawaii, which is currently being measured) are available in a Microsoft Access database called the PNW-FIA Pacific Islands Database. The application contains a user-friendly front-end Interface with a series of push buttons and pop-up screens that simplify a variety of tasks.

The Interface makes it easy to view data and run summary reports for Island-specific projects. Users can open up the database window to work directly with the raw data if desired. There are options to browse through the entire database, plot by plot, or to select a subset of plots for individual analyses.

The application, data, field manuals, publications, and data dictionary have been zipped and are available to download or request on CD.

Note: Data from the inventory of Hawaii will be made available in FIADB format once the inventory is complete.


The inventory schedule for Pacific Island Groups is shown below:

Year(s) Island group name
2001, 2012 America Samoa
2002, 2013 Guam
2003, 2014 Palau
2004, 2015 Northern Mariana Islands
2005-2006 Federated States of Micronesia
2008 Marshall Islands
2010-2015 Hawaii

IDB-Integrated Database: Periodic Forest Inventory Database, 1988-2000 (CA, OR, WA)

The PNW-FIA Integrated Database (IDB) contains periodic inventory data collected by PNW-FIA, the National Forest System (NFS: Regions 4, 5 and 6), and the BLM for California, Oregon, and Washington. Dates of the inventories range from 1988 to 2000. Data acquired from each inventory program were compiled into one database with a common set of formats, definitions, codes, measurement units, column names, and table structures. When possible, the same procedures, algorithms, equations, and calculation methods were used to compile all inventory data in the IDB. This database contains an extensive amount of measured and calculated information for each inventory plot.

Quick Overview

In response to the high demand for forest inventory data, a database was developed (the PNWFIA-Integrated Database, or “IDB”) from inventories available from the National Forest System, BLM, and PNWFIA. Data acquired from each inventory program were transformed into databases with a common set of formats, definitions, codes, measurement units, column names, and table structures.

The result is an integrated database, where items such as net volume, current annual growth, or forest type are calculated with the same methods. Our goal was to produce a database that is easy to use, well documented, and standardized across owners and states.

Source and dates of forest inventory data:

Data source name Primary states Dates of inventory
Region 5, Pacific Southwest CA 1993-2000
Region 6, Pacific Northwest OR, WA 1993-1997
Bureau of Land Management Western OR 1997
FIA, Eastern Oregon OR 1998-1999
FIA, Western Oregon OR 1995-1997
FIA, California CA 1991-1994
FIA, Eastern Washington WA 1990-1991
FIA, Western Washington WA 1988-1990

Version 2.0 was completed in 2005.

Current inventory data is being compiled and released in the PNW-FIADB.


National FIADB and Tools: Links to the National Forest Inventory Database for all states

Links to the national FIA website:

Link to FIATOOLS Link to DATIM Link to FIA DataMart

Annual (PNW-FIADB) Versus Periodic (IDB) Inventories

Starting in 2000, as required by the Agricultural Research Extension and Education Reform Act of 1998 (the Farm Bill), FIA implemented a new standardized national inventory method in which a portion of all plots in each state were measured each year. In the Pacific Northwest, one-tenth of all forested plots (referred to as one panel) are visited annually, with all plots in any given state being sampled over a ten-year cycle (including national forests and parks).

Data from new inventories are often compared with earlier inventories to determine trends in forest resources. However, several changes in procedures and definitions were made when FIA shifted to an annual inventory, and the procedures must be similar for comparisons between two inventories to be valid. Changes to FIA protocol included an increase in plot density of about 18 percent, a new plot footprint (changing from a five-subplot configuration distributed over a 6-acre area, to a four-subplot configuration over a 2.5 acre area), and a new set of nationally consistent measurement protocols.

These changes will have little impact on statewide estimates of forest area, timber volume, and tree biomass, but they may significantly affect plot classification variables such as forest type and stand size class. Estimates of growth, removals, and mortality are particularly dependent on comparisons between inventories, and thus are most likely to be valid when based on remeasurements of the same plots and trees. Estimates of GRM will improve as the annual inventory becomes fully implemented and several panels of plots are remeasured.