Osoyoos is right on the border with the US. Seattle is not too far away. But if you go here by bus don't take the Greyhound from Osoyoos (which goes through Vancouver). A quicker, cheaper and in some ways more interesting trip is to get someone to drive you to Omak, Washington (about an hour away over the border). From here you can catch a cheap bus to Seattle.
Omak also has a cool rodeo each year with the infamous "Suicide" horse race.