This classification requires that land be devoted to the production of livestock or agricultural commodities for commercial purposes. "Commercial agricultural purposes" is defined in WAC 458-30-200 and includes such activities as raising and selling lawful crops, livestock, dairying, animal husbandry, Christmas trees, and certain equestrian-related activities. The land must be used on a continuous and regular basis that demonstrates the owner intends to obtain a monetary profit through those activities. Raising crops or animals for a family's own use, enjoyment, or consumption does not qualify. All land classified as OSFA must meet income requirements based on the amount of acreage so classified.

New applications are submitted to the Cowlitz County Assessor's Office for approval or denial and must include a non-refundable application fee of $453.50 (includes $303.50 in mandatory recording fees).

Once land is classified, the Assessor's Office maintains the files for all property in the Open Space program, including maintaining a dual tax roll to track the Current Use value (taxable) and the true and fair value (market). The Assessor is also responsible for conducting periodic reviews including on-site inspections to make sure the land is still being used for the purpose for which it was granted classification. If land is no longer being maintained according to the approved Open Space agreement, it will be removed from classification and an Additional Tax will be assessed, including interest and a 20% penalty.