The creation of the Cabazon dinosaurs began in the 1960s by Bell to attract customers to his Wheel Inn Restaurant, which opened in 1958 and closed in 2013. Dinny, the first of the Cabazon dinosaurs, was started in 1964 and created over a span of eleven years. Bell created Dinny out of spare material salvaged from the construction of nearby Interstate 10 at a cost of $300,000. The biomorphic building that was to become Dinny was first erected as steel framework over which an expanded metal grid was formed in the shape of a dinosaur. All of it was then covered with coats of shotcrete (spray concrete). Bell was quoted in 1970 as saying the 45-foot-high (14 m), 150-foot-long (46 m) Dinny was "the first dinosaur in history, so far as I know, to be used as a building." His original vision for Dinny was for the dinosaur's eyes to glow and mouth to spit fire at night, predicting, "It'll scare the dickens out of a lot of people driving up over the pass." These two features, however, were not added.

A second dinosaur, Mr. Rex, was constructed near Dinny in 1981. Originally, a giant slide was installed in Rex's tail; it was later filled in with concrete, making the slide unusable. A third woolly mammoth sculpture and a prehistoric garden were drafted but never completed due to Bell's death in 1988.