The El Camino “passenger-car pickup” first appeared in 1959 and was, along with the ’60 edition, based on the full-size Chevy. Following a three-year hiatus, the El Camino returned for 1964, as a derivative of the new intermediate-sized 1964 Chevelle. The restyled ’68 El Camino was as sleek as any vehicle with a pickup bed could be. That same year, the El Camino was finally available with Super Sport equipment, and buyers could fully partake of the additional muscle-car options offered for the Chevelle SS. The 1970 El Camino SS, stuffed with 396- or 454-cid Chevy big-block power, is the ultimate El Camino of the muscle car era.
Although based on corresponding Chevrolet car lines, the vehicle is classified and titled in North America as a truck. GMC's badge engineered El Camino variant, the Sprint, was introduced for the 1971 model year. Renamed Caballero in 1978, it was also produced through the 1987 model year.
El Camino is Spanish for "the road" or, alternatively, "the path", or quite literally, "the walk".
Sources: GM Heritage Center and Wikipedia, 2011