This research estimated dynamic supply and demand equations for the U.S. softwood lumber using two-stage least squares. Long-run and ECM equations were derived from the estimated coefficients. Empirical data included monthly observations from 1990 to late 2006. Stationarity of the residuals was explored using Augmented Dickey–Fuller statistics. Results suggest that demand and supply elasticities in both short and long-run are relatively small compared with past studies. The Canadian softwood lumber supply to the U.S. is more price elastic than the domestic softwood lumber supply. U.S. import tariffs have had limited impact on the amount of softwood lumber imported from Canada. Technological progress and end-of-year seasonal effects on softwood lumber demand and supply were significant over this period.