Should the American laws stand, McPeak foresees the same happening to Seattle.
Marijuana "has been an emerging market in some states. It's reasonable to assume that entrepreneurs will try to take advantage of this in a new way."
In Denver, some feared that Colorado marijuana vote could deter tourists, not to mention business visitors.
"Colorado's brand will be damaged, and we may attract fewer conventions and see a decline in leisure travel," Visit Denver CEO Richard Scharf said in a statement before the vote.
Colorado's governor opposed the measure but said after its passage that he didn't envision marijuana tourism materializing.
"I don't think that's going to happen," Democratic Gov. John Hickenlooper said.
"They're going to flock here to buy marijuana as if they're going to take it back? On an airplane? That seems unlikely to me. I think those kinds of fears are overblown."
Colorado's measure specifically bans public use of the drug. But guidelines for commercial sales are still to be worked out. The state's 536 medical marijuana dispensaries are banned from allowing on-site consumption, meaning patients have to take the drug home with them. But lawmakers could set different rules for recreational marijuana shops, including the possibility of marijuana cafes.
Marijuana backers downplayed the impact on tourism. Aldworth pointed out that pot-smoking tourists wouldn't exactly be new. Colorado ski slopes already are dotted with "smoke shacks," old mining cabins that have been illicitly repurposed as places to smoke pot out of the cold. And the ski resort town of Breckenridge dropped criminal penalties for marijuana use two years ago.
"Some folks come to Colorado and enjoy some marijuana while they are here today," Aldworth said.