Capital Gains Determination
Based on your responses you sold standing timber (stumpage), that was "held primarily for sale to customers in the ordinary course of a trade or business", as a lump sum sale, under a pay-as-cut contract, but you did not retain an economic interest in the timber that was sold.
In order to qualify under Section 631(b), disposal with an economic interest retained, there are certain qualifications that must be met. The first being that an "economic interest" in the timber is retained. Since you did not, the transaction does not qualify for capital gains treatment, and the income from the transaction must be reported as ordinary income on the appropriate business form.