Yesterday the Colorado General Assembly gave final approval to legislation aimed at implementing Amendment 64, the marijuana legalization initiative enacted by that state's voters last November. H.B. 1317 establishes a framework for regulating the state-licensed pot stores that are supposed to start opening next year, while H.B. 1318 imposes a 15 percent excise tax and a 10 percent special sales tax on marijuana. The Colorado Department of Revenue now has until July 1 to write detailed regulations, while the new taxes must be approved by voters this fall before they can take effect.