I realize that you meant to say
Washington and Colorado, but Oregon does have it's own form of Pot Tourism in existence (only in Summer though, as the rest of the year it is fucking RAINING CONSTANTLY)(yes, I think I might be suffering from Seasonal Affective Disorder)
The Summer festivals (Country Faire, several Hemp Festivals, Fairie World, Reggae Fest) all bring in a lot of tourists, and while weed is not the formal focus for some of these gatherings, it's everywhere! We recently voted to legalize dispensaries, so who knows how they will capitalize on the tourism thing.
I know I would pay money to go on a tour of the Stanley Brothers grow op in Colorado. I saw their set up on the Sanja Gupta MMJ special, and it was phenomenal.