stats for

THP Analysis


  • CDF = Calfire = California Department of Forestry
  • THP - Timber Harvest Plan
  • NTMP - Non Industrial Timber Management Plan (slightly different from a THP.)
  • RPF – Registered Professional Forester
  • LTO – Licensed Timber Operator
  • DBH – Diameter at Breast Height

Logging Terminology

  • Basal Area – The surface area on a theoretical stump if a tree was cut at breast height.
  • Clearcutting – Cutting most or all of the trees down in a given area. Clearcuts usually
    range in size from a few acres to 100’s of acres.
  • Selection – Taking all but 75 square feet of basal area per acre. Meaning, the trees remaining on an acre of ground would fit inside a 7.5 x 10 ft. rectangle.
  • Silviculture- Logging term equivalent to agriculture.
  • Rehabilitation of understocked Areas (Rehab) – Clearcutting and/or herbicide application on hardwood trees and bushes.
  • Variable Retention (VR)– Trees remaining after logging may vary depending on variables such as unit size.
  • VR Aggregate – Small groupings of trees remain amidst a clearcut. The trees retained usually cover about half an acre or less.
  • VR Dispersed – Similar to Selection logging.

How THP’s are organized

Note: Many of the pages in a THP are boiler plate documents meant to ward off environmental lawsuits. Though seemingly useless, they sometimes contain tidbits of useful information.

THP Numbers

THP’s are filed under a numeric code.
Here’s an example of a real north coast THP number.


The first number is the region in which the THP is located
(1= north coast region, 2= cascade region).
The second number is the last two digits of the year in which it was filed.
The third number is the order in which it was filed.
The last is the abbreviation for the county.

THP List

1. Go to the CDF THP List Website.

2. Look at the bottom of the north coast region section of the list to see the most recently filed THP’s.

THP Library
The place to download the full documents is the THP Library.

Here you can find all of the current THP’s for California. In the New Mail folder you may be able to find THP’s that are so new they are not posted anywhere else yet.

THP Documents

Section 1: “General Information” Land Owner, Licensed Timber Operator (LTO), Forester, Township and Range.
Section 2: “Plan of Operations” Contains Maps, Numbers on Silviculture
Section 3: “Supporting Documentation” Contains Forest Descriptions, Species information.
Section 4: “Cumulative Impact Assessment” Contains Past and sometimes theoretical Future Logging Unit Maps.

Documenting and Tracking THP’s

These are some of the aspects of THP’s worth tracking. These can be used to form a THP tracking chart.

• THP#
• Company/Land Owner
• Registered Professional Forester (RPF writes the plan)
• Watershed/Region
• Main Issues-Concerns
• Silviculture Acres- Cut, No-cut, Total
• Forest Description
• Filing Date
• Public Comment Period
• Pre-Harvest Inspection (PHI) Date
• 2nd Review Date
• Date of Decision
• Operation Start Up - Activation

Calling CDF For More Info.

There is some info that is hard to get without calling in. This includes up to date Start-Up notification.

You can call the Fortuna office of California Deptartment of Forestry (aka CDF, aka Cal Fire) at 707-725-4413.

When someone picks up tell them you have a question about  a THP and they will transfer you to the appropriate desk. Here you can inquire as to the status of THP’s.

Public Comment

You can email in comments on Northern Unit plans at-

Q: Why bother with commenting?

A: Comments can be used to help lay a foundation for a lawsuit. Without comments pertaining to your issue it can be next to impossible to successfully sue. Comments can also slow the THP approval process which can be strategically beneficial for obvious reasons. A flood of comments can send a political message and have unexpected effects on logging companies.