Can I deduct HOA fees for investment property -- raw land.

It is deductible, but where is determined by how the land is being currently used.

If the land is rented out (as pasture for example), the the HOA fees are a deductible as a Rental expense then.

If you are a land developer, then it is deductible as a Sch C business expense. 

If the land is not rented and held for investment only, the the HOA fees are a deduction as "Investment expense."

For the Investment Expense go to"

Federal Taxes (may be Personal tab in self-employed)

Deductions and Credits, then scroll down to "Other Deductions and Credits" and select 2nd from bottom: "Other Deductible expense" say, No, then Yes.  It is limited to deducting only the amount in excess of 2% of the adjusted gross income (TurboTax computes this, you just need to enter the amount).