The U.S. Energy Information Administration has released final data for their 2011 surveys. For residential use, they estimate that 22.5 million cords of wood were burned in 2011, equalling some $4 billion worth if averaged at $175/cord.
This chart shows state-by-state estimates of consumption in cords. with California coming out as the top consumer of firewood, with Missouri and Pennsylvania coming in second and third, respectively.
This chart shows the estimated cost per million BTUs in each state. This chart also compares costs of wood and biomass waste to firewood.