Do a Google search for "lumber industry" and choose NEWS from the list at the top. You'll find lots of news about the lumber industry, who would have known so much was going on! Here's an article from Forbes.
You might want to check out the History.com site for the series Ax Men, that profiles present day lumberjacks and has info on history on lumbering, would probably be ok for grade 4. Does have video clips from the series but advertisements of course since it is from History.com.