There are 14 US cities, with an urban area population of 20,000 or more, on its land border. The first 4 are adjacent to Canada, the remaining 10 adjoin Mexico. How many can you name?
Cities are listed as you travel each border in one direction
Minor thing- I guess Niagara Falls is technically east of Buffalo, but you're moving eastward along the border to get from Buffalo to Niagara. I was trying to figure out what random suburb of Detroit or Buffalo fit the criteria before getting it.
Yes, it's a line ball call there. There is clear countryside between Yuma and the Mexican border town of Algodones and San Luis, but as you say you could argue the same for McAllen, although McAllen's city limits do reach the border.