The Proposed Canada to Mexico Highway: US Highway 789

US Highway 789 was a proposal for a border-to-border highway running from Nogales, AZ at the Mexican border, to Sweet Grass, MT at the Canadian border. It was dubbed the "Canada-to-Mexico Highway".

It was rejected by AASHTO, given that much of the route would use already existing US Highways (not that that's ever stopped them since). Nonetheless, each state (Arizona, New Mexico, Colorado, Wyoming, and Montana) was interested in a continuous route, and so each created or proposed a Route 789 in their state highway system during the early 1950's.

Colorado's 789, sharing pavement with US-160 and the formerly numbered US-666 (now 491). Image: Jim Lindsay

In Arizona, AZ-789 was designated in 1956. Over time, given the duplicative nature of the numbering, each state except for Wyoming chose to remove the 789 designation from their systems. 

US 310 in Wyoming, along with WY-789, which was once proposed to be its own US Route. Image:  Jonathan Winkler via

In Wyoming, 789 is presently the longest state route in Wyoming's state highway system at 407 miles.

Based on the route description given from AARoads, I have mapped what the present-day route would look like if it was actually constructed below:

In Colorado, CO-789 was realigned after 1961. It originally followed present-day US-550 into New Mexico from Farmington, and the new alignment, as shown above, followed US-666 and US-160 (or US-164)

While it is true that much of the route would be duplicitous, and completely pointless today in the face of the Interstate highway, where one could easily follow pretty much the same route by taking Interstate 19, 17, 40, 25, 90 and 15, I think it's interesting that this proposal was rejected, but something like US-400 was approved, which in addition to being a violation of traditional US Highway numbering rules, has extremely long stretches of concurrency with US-50 and US-54, among other routes. 

The Canada-to-Mexico Designation of the highway was also heavily promoted, and in fact a souvenir photo album of postcards from the highway in Colorado was produced, under the assumption that CO-789 would eventually become part of the US Highway.

The photo album is shown below, as I happened to find a copy on eBay. It appears that the boosters of the road believed it would eventually connect Canada and Mexico, and attempted to future-proof their descriptions, since US-789 never existed, let alone connected the entirety of the proposed route.

The excerpts below each image are found on the postcards on the reverse of the image. 

Front cover of the album in gold; the lines are from my scanner and represent null colors, since the outline of the book is hollow.

"Balcony House, cliff dwelling in the Mesa Verde National Park...easily reached from Hyw [sic] 789 from either Durango or Cortez. These ancient ruins are the most popular tourist center in all southwest Colorado." Ektachrome Slide. O. Roach of Lakewood, CO.

"Engineer Mountain...most prominent landmark on Hyw [sic] 789 between Durango and Silverton. Durango is the southern terminus of the narrow gauge tourist trip up the Animas Canyon, and is also the eastern gateway to the Mesa Verde."

"Silverton, Colorado...famous mining town in early days and far from a ghost town now. This town on Hwy 789 is on the south end of the Million Dollar Highway (part of 789), and on the north terminus of the last of the famous narrow gauge passenger trains still operating."

"Red Mountain...most colorful of all the 14,000 "footers" in Colorado, as seen from Hwy 789 (here known as the Million Dollar Highway) just a few miles from the equally colorful mountain town of Ouray, where much of Colorado's early mining history was made." Kodachrome, Edwin R. Brown Studio, Lakewood, CO.

"Black Canyon of the Gunnison...a famous yet short side trip off Hwy 789 from either Delta or Montrose, CO. Here is some of the most breath-taking scenery in all the West." Ektachrome, Monk & Parma, Tyson, Hotchikiss, CO.

"Rifle Shale Oil Plant just off Hwy 789...nestled among colorful cliffs...a striking scene of giant industry in the heart of an American wilderness." Ektachrome, Robt. Beverly, Grand Junction, CO.

"Trappers Lake, second largest natural lake in Colorado, a glorious side trip off Hwy 789 into the heart of the Meeker big game country. Take it traveller [sic], you'll never begrudge the time." Ektachrome, D'Agee, Meeker, CO.

"Independence Rock in the Colorado National Monument, just a fifteen minute drive off Hwy 789 from Grand Junction, CO. Open all year. Cool in the summer and mild for winter picnics.

The pictures quite obviously speak for themselves, and not just in Colorado, this would have been an incredibly scenic journey, and remains an incredible drive from Mexico to Canada, even if it doesn't carry a single number. I like the idea of 789, and I think it's a shame that it never came to be, even if I understand the reasoning behind it. 

Thanks as always for reading!


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