Miss. Code Ann. § 27-25-7: Miss. Code Ann. § 27-25-7

If any person liable for any tax under this article shall ship or transport his timber or timber products, or any part thereof, out of the state, without making a sale, then the quantity or value thereof, as the case may be, in the condition or form in which they existed immediately before transportation out of the state, shall be the basis for the assessment of the tax imposed by this section.