Under an impossibly blue Sonoran sky, the quiet main plaza of San Luis Río Colorado stretches out in this vivid chrome-era postcard — a sleepy border town's commercial heart anchored by the eye-catching neon and blade sign of Cinema Curto, one of the town's beloved neighborhood movie houses, while a farmacia sign peeks in at far right and a lone cyclist waits at the traffic light. The vintage blue sedan in the foreground and the low-slung mid-century storefronts place this image firmly in the 1970s. San Luis Río Colorado sits at the northwest tip of Sonora on the Colorado River, just across from Yuma, Arizona — a town that grew rapidly after post-war irrigation projects transformed the surrounding desert. This card was never mailed, retaining its fresh, unused condition with rounded corners typical of the Mexfotocolor format.