How do I subdivide property zoned as timber (TBR) in Clackamas County OR?

I will give you a quick answer on this one, just in case you have not taken action.

I am a California Licensed Attorney and I cannot give you legal advice for your issue in Oregon; you will need to consult an Oregon Licensed attorney in the county where the property is located.

However, I am convinced that you need a land use attorney. There are multiple legal issues that jump out at me based on my experiences in Monterey County, California. Again, these may not apply in Oregon but it will give you an idea of why you need an attorney if you have not considered them. Also, this is a knee-jerk response to your question and research based on your particular facts would likely reveal more.

1) Legal lots and merger are very, very complicated. There are many reasons why a county will not recognize legal lots, and a good attorney will be able to tell you with a fair degree of certainty if you have legal lots. Just because the county tells you they are not legal lots, that by no means indicates that they are not in fact legal lots.

2) You should get clarification of what this "some zoning rule" is and provide the cited rule to your attorney. It will save you money because the attorney won't have to do the legwork to get that information. Time is money and if you can do it yourself, why not do it. Unless you have more money than time, which is often the case with clients with regular issues dealing with land use law. Still, based on the fact that you are trying to go it alone, my guess is that you want to minimize your legal expenses to the maximum extent practicable.

3) The fees you will pay to the county may be as significant as the fees that you pay to your attorney. However, if you don't get an attorney you very likely are wasting your money by making the application to the county because they have already decided against you before you even started. Without legal representation, my experience tells me that any planning department is going to stick to their original conclusion and prevent you from doing what you want to do in this case.

Finally, be prepared for an attorney to tell you that the county is correct. That just might be the case.