Canada, America's neighbor to the north, is the second largest country in the world. Visitors from the United States enjoy easy access to the sights and attractions in this vast country's major cities and rural areas by presenting required documents when crossing the border between the two nations. Travel document requirements vary, depending on your citizenship status, age and mode of travel.

All U.S. citizens can use a valid passport to enter Canada by land, sea or air. Canadian immigration prefers machine-readable passports. Passport cards – wallet-size travel documents – allow U.S. citizens to enter Canada and return to the United States only by land or sea. U.S. military personnel can use an official military I.D. card to enter Canada at any port. Legal residents of the United States need a valid passport issued by their country of citizenship and their Green card to enter.

Children

Canada has special documentation requirements for adults who travel with children and unaccompanied minors under age 16 entering the United States. Every child must have a valid passport or passport card issued in his name or be included on the traveling parent's passport. An original birth certificate establishes the adult's relationship with the child. An unaccompanied minor must present a letter from the guardian or adult in Canada who is responsible for the child after entry.

A noncustodial parent who travels with a minor child must have a letter from the custodial parent that includes contact information and a statement giving the traveling parent permission to bring the child into Canada. This letter must specify the duration or dates of the visit. To facilitate entry, have a copy of any court orders that pertain to the custody of the child and divorce decrees as applicable. A legal guardian must present a copy of the court order appointing her as the child's guardian.

U.S. Foreign Visitors

Except for nationals of countries on Canada's visa-exempt list, foreign tourists and students temporarily in the United States must apply for a visa to travel to Canada from the United States. Citizens of most, but not all, former and current member countries of the British Commonwealth and dependent territories, many countries in the European Union, and nationals of Taiwan generally will not need a visa and may enter from the United States with a valid passport.

Trusted Traveler Options

Canada provides two trusted traveler options for U.S. visitors who cross the border frequently. The CANPASS allows U.S. citizens and Green card holders to enter Canadian ports by air or water, using commercial, private or corporate transportation. You can also use it to cross the border in specified remote areas, such as the lakes and locks that connect Canada and the United States. Apply for the pass that fits the mode of travel that applies to your most frequent visits. The NEXUS program, run jointly by the United States and Canada, allows permanent residents and U.S. citizens of both countries to register as a frequent traveler.