You know that is a great question..My first thought was simple just go here

https://help.cbp.gov/app/answers/det...-united-states

And just assumed it would be almost impossible or cost prohibitive. Heck NY state doesn't even want us to move firewood from place to place within the state.
But then I thought about the wood carvings I brought home with no trouble at all....Hmmmm makes you think.
So I am of little to no help at all except I will be watching for a good response on this question.