FOrest and natural resources valuation can present challenging analysis and appraisal problems. Calculations range from specialized problems like bare land value to standard criteria like net present value and internal rate of return. Financial calculators are fine for simple analyses but forestry problems tend to be complex and often require the use of a computer investment analysis program. FORVAL is a user-friendly, free, menu-driven forestry and natural resources investment analysis program. It contains all the standard tools used in discounted cash flow analysis, plus financial criteria and valuation procedures that are unique to forestry. We describe the program, how to use it for forestry and timber valuation analysis, and explain the basic forestry valuation theory behind the procedures. Formulas and financial valuation theory behind the procedures. Formulas and financial criteria are footnoted back to the basic appraisal literature. FORVAL is appropriate for any general appraisal valuation problem.