When I am not agmantoo, I am in forest products. I have a tree enterprise and I sell the production from my tree farms. Do as Jena suggested but I doubt that the state forestry people will give you a quote as to the value. However, they willl provide a list of private foresty management individuals. Pay for someone to come and take inventory of your walnut trees. Then you can prepare a request for bids from the various buyers in your area. The professional that did the inventory may also have some contacts. You need to find an end user with a need since you have such an uncommon species. You should recoup the fees plus generate the maximun return using this technique. Never take a bid from a harvester without knowing the quantity of you timber. You only have a once in a life time opportunity to harvest such trees from this tract of land and you need to make the most of it. Capital gains from the harvest are low at this time so the timing is good if the market for walnut is good. I wish that I had some walnut to sell as I am into the cheaper varieties. PS, with this approach you can get paid in advance and not get ripped off by the harvester failing to pay for the last loads he cuts. Get a good understanding, in writing, as to how the property appear after the harvest . You state forester will see to it that the correct harvesting techniques are followed if you will ask him to check during the harvest.