Shot from nearly the identical vantage as its companion card, this second A.M. Lopez real-photo postcard of Cuesta de Mamulique reveals subtle but telling differences — the bus has moved further around the lower hairpin, and the print exhibits slightly stronger contrast, throwing the Sierra Madre ridgeline into sharper relief against the bright sky. Collectors of Mexican highway history prize pairs and variants like this for documenting how Lopez worked a scene, repositioning or timing traffic to vary his compositions. The Carretera Nacional through Nuevo León was inaugurated in stages through the late 1930s, and photographers like Lopez were instrumental in promoting the route to both Mexican and North American motorists who were newly free to drive across the border.