From Seattle, take the I-5 North to the border crossing in Blaine, Washington (Pacific Truck Crossing).
Follow 176th Street and turn west on the Trans Canada Highway #1.
Follow the signs to Whistler, along Highway 99 Sea to Sky Highway.
Another option is to take the Peace Arch Crossing, and continue on Highway 99 into Vancouver.
Travel across Lions Gate Bridge and follow Highway 99 Sea to Sky Highway.