Obtain a valid proof of American citizenship before traveling to Canada. According to the Western Hemisphere Travel Initiative, customs officials accept U.S. passports or NEXUS enrollment cards for travel to Canada in any form. U.S. passports, enhanced driver's licenses, SENTRI cards and FAST cards are accepted to return from Canada by land or sea, but not by air. NEXUS, SENTRI and FAST cards are available through the U.S. Customs and Border Protection Trusted Traveler Programs (goes-app.cbp.dhs.gov). They are identification cards showing that the holder has been pre-screened for secure border crossings, and they allow expedited travel for the holder.
Drive across the Canadian border. From Seattle, follow Interstate 5 north toward Canada for 111 miles to the Peace Arch Crossing near Blaine, Washington. Follow the traffic signs to drive in the appropriate lane. If you are stopped, present your identification and follow instructions from the customs officer. When you are allowed to drive forward, the road changes to Canadian Route 99, which will take you to Vancouver. Alternately, drive 90 miles from Seattle on I-5, then take Exit 265A near Bellingham to Route WA-539. Follow Route WA-539 to the Pacific border crossing. After crossing, follow Canadian Route BC-13 to BC-1 west, also known as Grandview Highway, to Vancouver.
Cruise on a ferry from Seattle to Vancouver. There is no ferry that travels directly between the two cities (as of June 2011), but you can travel from Seattle to Victoria on the Victoria Clipper (clippervacations.com), then take a Pacific Coach bus (pacificcoach.com) to the Swartz Bay Ferry Terminal to catch a British Columbia Ferry (bcferries.com) to Tsawwassen Ferry Terminal. From Tsawwassen take another Pacific Coach bus to downtown Vancouver. The Victoria Clipper does not transport vehicles, so if you'd like to keep your car with you, drive north from Seattle to Anacortes to take a Washington State Ferry (wsdot.wa.gov/ferries/index.cfm) to Sidney, British Columbia, or drive to Port Angeles to take a Black Ball Ferry (cohoferry.com) to Victoria. Once on Vancouver Island, drive to the Swartz Bay Ferry Terminal to link with a British Columbia Ferry that can take you and your vehicle to the Canadian mainland.
Fly from Seattle's Sea-Tac Airport (portseattle.org) to Vancouver International Airport (yvr.ca). Air Canada (aircanada.ca), Alaska Airlines (Alaska-air.com), Horizon Air (horizonair.com) and United (united.com) fly directly between Seattle and Vancouver, as of June 2011. You must have a U.S. passport to cross the Canadian border by air.
Travel by train on the Amtrak Cascades line (amtrak.com). Purchase a train ticket online or at Seattle's King Street Station (seattle.gov). The train arrives at Vancouver Pacific Central Station (viarail.ca) in downtown Vancouver. Vancouver's public transportation (translink.ca) takes visitors from Central Station throughout downtown.
Ride a bus from Seattle to Vancouver. Three bus lines offer transportation:
Quickshuttle (quickcoach.com), Amtrak's buses (amtrak.com) and Greyhound (greyhound.com).
