Officially US Route 89 goes from Flagstaff, Arizona, to the Canadian Border. That distance is 1,342 miles (2,160 kilometers). The historic route of US 89 between Nogales and Flagstaff is 418 miles (673 kilometers). The total length of Highway 89 between Canada and Mexico is 1,760 miles (2,832 kilometers). In addition there are two alternative routes—AZ 89A is 92 miles (148 kilometers) and US 89A is 93 miles (150 kilometers). To drive all of Highway 89 including the alternatives is a total distance of 1,944 miles (3,129 kilometers).

Suppose you plan to drive the entire length of US Route 89. In that case, the best time is from July to September, starting at Glacier National Park on the Canadian border. Glacier and Yellowstone are the last parks to fully open in the summer. Ideally, allow three or four weeks for the journey to fully enjoy everything there is to see, although it can be done in two weeks. The later you start, the cooler it will be when you get to Arizona. Of course, summer is the busiest time for all the parks and other tourist attractions from the Grand Canyon to Glacier. Therefore, it is good to make reservations for the park lodges well in advance and the same for campgrounds where available.

Southern Arizona is best visited from October to May unless you like the heat. When conditions are right, spring wildflowers bloom from March to May and cactuses put on their best show in the spring.

Northern Arizona and southern Utah are year-round destinations. The Grand Canyon, Zion and Bryce Canyon National Parks are open and accessible all year. You’ll experience moderate temperatures and weather in the spring and fall. Summer can be hot but not unbearably so. You can expect snow in the winter, enhancing the region’s beauty. The one exception is the North Rim of the Grand Canyon, which is only open in the summer, usually from the middle of May to the middle of October, depending on snow conditions.

Travel on US Route 89 in Wyoming and Montana is very weather-dependent. Most of the facilities in Glacier National Park close in early September and reopen in late May. The visitor’s center at St. Mary is open all year, providing access for winter activities. Depending on snow conditions, Glacier National Park roads usually are plowed and open in June but sometimes as late as the middle of July. In Yellowstone National Park, the Mammoth Hot Springs Visitors Center is open all year. Other facilities and park roads close in September and reopen in May or June. In the winter, access to Yellowstone is by cross country skies, snowmobile or snow coach. Grand Teton National Park is similar to Yellowstone in its seasonal hours and road closures.

Read this article for help in getting current road conditions.

From south to north, US Route 89 passes through Arizona, Utah, Idaho, Wyoming and Montana.

Saguaro and Grand Canyon National Parks in Arizona, Zion and Bryce Canyon National Parks in Utah, Grand Teton and Yellowstone National Parks in Wyoming and Glacier National Park in Montana.

In Arizona, Tumacácori National Historical Park, Casa Grande Ruins, Tuzigoot, Montezuma Castle, Walnut Canyon, Sunset Crater Volcano and Wupatki National Monuments. Glen Canyon National Recreation Area and Vermilion Cliffs National Monument straddle the border of Arizona and Utah. In Utah, Rainbow Bridge Grand Staircase-Escalante and Cedar Breaks National Monuments.

Basin and Range in Arizona, Colorado Plateau in Arizona and Utah, Rocky Mountains in Utah, Wyoming and Montana, Great Plains in Montana.

Tohono O’odham (San Xavier) and Navajo Reservations in Arizona and Blackfeet Reservation in Montana.

In Arizona, there are two major airports—Tucson International and Phoenix Sky Harbor. Smaller airports are located in Flagstaff, Page and Tusayan (Grand Canyon). In Utah, Salt Lake City International is the only major airport. In Wyoming, Jackson Hole Airport in Jackson is the closest to US Route 89. In Montana, Bozeman Yellowstone International is the largest airport. Great Falls International in Great Falls and Glacier Park International in Kalispell provide access to US Route 89.

The Piegan/Carawy Port on US Route 89 connects the United States and Canada on the east side of Waterton-Glacier International Peace Park. The hours of operation are from 7:00 am to 11:00 pm but are subject to change. You will need to have a current US passport or passport card. Canadians will need a current passport. You may also be asked to show a driver’s license, vehicle registration and proof of insurance. This port is in a remote location with no motorist services.

It is easy to walk across the border at the Nogales-Grand Avenue Port of Entry. Take Interstate 19 south from Tucson to the exit marked International Border. Park in one of the many lots which charge a small fee then walk through the border gate into Nogales, Sonora. You will find many shops and restaurants to choose from for a day of shopping and dining. Cash is preferred and credit cards are not widely accepted. Bargaining on price is expected so don’t hesitate to ask for a better price. When you cross back into the US you will need a passport or passport card. In general, you can bring back up to $400 in goods without paying a duty.

Driving your car into Mexico is more complicated. Your American car insurance is not valid in Mexico so you will need to purchase Mexican car insurance which is available in towns near the border. There are other considerations which you should research thoroughly before deciding to drive in Mexico. Check out the article as a start.

Until the 1920s, interstate roads in America were created by private booster groups and given names such as the Lincoln Highway, the Old Spanish Trail, and the National Old Trails Road. Then, as traffic increased with over ten million cars registered, state highway officials asked the federal government to help replace this confusing and unregulated system with a standard method of designating highways. The result was a numbering system for interstate highways announced in 1925.
The plan was simple in concept but required numerous compromises in execution. East-west roads were given even numbers, north-south roads were given odd numbers. Transcontinental east-west routes had numbers ending in zero with US Route 2 in the north to avoid a US Route 0. Main north-south routes ended in one starting in the east. Other multi-state routes were fitted within the resulting grid.
In the 1925 plan from the US Department of Agriculture’s Bureau of Public Roads (BPR), US 89 was a minor route connecting Thistle, Utah, and Flagstaff, Arizona.
The BPR plan was turned over to the American Association of State Highway Officials (AASHO) for revision and approval. Over the next two years, numerous meetings were held and compromises were reached to produce the final US numbered highway system in November 1927. The total mileage of selected roads was 96,626.
US 89 had grown to 917 miles beginning in Spanish Fork, Utah, ending at the Mexican border at Nogales, Arizona.
In 1934, US 89 became a border-to-border route when it was extended to the crossing station at Piegan, Montana. The total length was 1685 miles.
From 1940 to 1992, an alternate scenic route, US 89A, was designated between Prescott and Flagstaff, Arizona, running through the Verde Valley and Sedona.
Construction of Glen Canyon Dam on the Colorado River in northern Arizona began in 1956. In 1959, US 89 was rerouted from Bitter Springs to Page and across southern Utah to Kanab with the completion of a bridge at the dam. The original route which crossed the Colorado River at Marble Canyon was designated as an alternative. It is now officially US 89A crossing the Kaibab Plateau north of the Grand Canyon.
In 1992, US Route 89 from Nogales to Flagstaff, Arizona, was decommissioned as a Federal Highway. The following replaced it numbered routes: Interstate 19, Nogales to Tucson; AZ 77, Tucson to Oracle Junction; AZ 79, Oracle Junction to Florence Junction; US 60, Florence Junction to Wickenburg; AZ 89, Wickenburg to Ash Fork; and Interstate 40, Ash Fork to Flagstaff.
By visiting the twenty National Parks and Monuments on US Route 89, a traveler can see a cross-section of the North American continent. There are the glacier topped mountains of the Rockies, the geysers of Yellowstone, the red and pink and white cliffs of the Colorado Plateau, the mile-deep Grand Canyon, and the green desert of broad valleys ringed by jagged mountains. The history of the West is also revealed along the road from Native American cultures to Spanish exploration to fur trappers and miners and cowboys, to Mormon pioneers and, finally, the growth of great American cities.
US Route 89 is truly America’s Most Scenic Road Trip.