Cal. Rev. & Tax. Code § 434.5

(a) On March 1, 1984, for the Redwood Region and Pine-Mixed Conifer Region, and on January 1, 1985, for the Whitewood Subzone of the Redwood Region, and January 1 of each year thereafter, the value per acre of timberland zoned under the provisions of Section 51110 or Section 51113 of the Government Code shall be determined from the following schedule:

(1) “Redwood Region” means all those timberlands located in Del Norte, Humboldt, Sonoma, Marin, Monterey, Santa Cruz, and San Mateo Counties and that portion of Mendocino County which lies west and south of the main Eel River.
(2) “Whitewood Subzone of the Redwood Region” means that timberland located within the Redwood Region within which the assessor has determined that redwood did not exist as a species in the composition of the original timber stand, or which has not been replanted with redwood for commercial purposes.
(3) “Pine-Mixed Conifer Region” means all other timberlands outside the Redwood Region.
When the assessor, pursuant to Section 434, designates a timberland parcel or portion thereof as inoperable, that timberland parcel or portion thereof shall be valued as if it is Site V.

Redwood Region
Site I	$180
Site II	$150
Site III	$130
Site IV	$114
Site V (and inoperable)	$ 35
Pine-Mixed Conifer Region
Site I	$ 98
Site II	$ 69
Site III	$ 56
Site IV	$ 39
Site V (and inoperable)	$ 23
Whitewood Subzone of the Redwood Region
Site I	$130
Site II	$ 95
Site III	$ 80
Site IV	$ 60
Site V (and inoperable)	$ 30

For purposes of this section:

(b) In 1985, the board shall determine the current value of timberland by the following process:
1. (1) For each fiscal year between July 1, 1979, and June 30, 1984, divide the total value of all timber harvested within the state, less miscellaneous forest products not reported by board foot volume, by the total volume of timber harvested, as reported pursuant to Section 38402. Average the five fiscal year values to obtain the five-year periodic immediate harvest value.
2. (2) For each fiscal year between July 1, 1978, and June 30, 1983, follow the same procedure as described in paragraph (1).
3. (3) Divide the value obtained by paragraph (1) by the value obtained by paragraph (2) to obtain the percentage change, rounded to the nearest one-tenth of 1 percent.
4. (4) Increase or decrease to the nearest dollar the full market values contained in subdivision (a) by one-half of the percentage change determined by paragraph (3).
(c) Beginning January 1, 1986, and each year thereafter, the board shall determine the current value of timberland using the same procedure as described in subdivision (b), except that this adjustment shall be made to the prior year’s adjusted values, and the five-year periodic immediate harvest values shall be successively one year more recent.
(d) The board shall certify the values determined pursuant to this section to the county assessors by November 30 of each year.
(e) The Legislature finds and declares that the foregoing values are consistent with the taxation of timberland used primarily for growing timber and that these values are consistent with the intent of subdivision (j) of Section 3 of Article XIII of the Constitution.