The original basis of the land would be its fair market value when you took possession of it. You may be able to determine this by doing some research online at the property appraiser's office.
All of the other expenses accept the property tax can be added to the basis of the land and deducted from the sale proceeds to determine your capital gain. The property tax was deductible each year on your personal tax return so you can't add it to your basis, unless you had made an election to capitalize all of your holding costs.
Also, if you had deducted any costs of the Timber when you sold it, you would need subtract that from your basis.
You report the sale as an investment sale in TurboTax, as follows:
While in the Federal section of TurboTax:
1. Income and Expenses
2. Investment Income
3. Stocks, Cryptocurrency, Mutual Funds, Bonds, Other (1099-B)
Choose the category of investment you want to enter and follow the instructions to enter your investment sale.
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