William Cahill of Cincinnati, Ohio, thatches a roof onto one of a series of huts made from stumps of a 227-year-old white oak in the Bookworm Glen section of the Pittsburgh Botanic Garden in Oakdale on Monday, Nov. 23, 2015. (Michael Henninger/Post-Gazette)
William Cahill of Cincinnati, Ohio, thatches a roof onto one of a series of huts made from stumps of a 227-year-old white oak in the Bookworm Glen section of the Pittsburgh Botanic Garden in Oakdale on Monday, Nov. 23, 2015. (Michael Henninger/Post-Gazette)