In this photograph taken with a zoom fisheye lens Saturday, April 25, 2015, walls of marijuana dry as a contingent of lawmakers, their staffers and a handful of lobbyists tour one of two retail and grow operations for both medical and recreational marijuana in northeast Denver. Colorado's unusual tax law is forcing the state to suspend taxes on recreational marijuana for one day, Sept. 16, during which a 10 percent sales tax and a 15 percent excise tax will not be collected. (AP Photo/David Zalubowski)