Douglass conducted excavations at the site, known as the Carnegie Quarry, for about the next fifteen years. Most of these collections were made for the Carnegie Museum, but the Smithsonian Institution and the University of Utah also received material from the site. Dynamite was often needed to blast through the overlying rock layers, and over 350 tons of fossil material was shipped back to the Carnegie Museum. Among the important specimens collected during this period are a number of nearly complete skeletons, including those on display at the Carnegie Museum. The juvenile Camarasaurus is the most complete sauropod ever found. A cast of this spectacular specimen has been returned to Dinosaur National Monument to be exhibited at the Quarry Visitor Center.
The dinosaurs that have been excavated from the site include the plant-eating sauropods Apatosaurus (also known as Brontosaurus), Camarasaurus, Diplodocus, and Barosaurus; the meat-eating theropods Allosaurus, Ceratosaurus, and Torvosaurus; and the plant-eating ornithischians Camptosaurus, Dryosaurus, and Stegosaurus. In addition to the dinosaurs, the quarry has yielded the remains of two kinds of crocodiles, two kinds of turtles, a frog, freshwater clams (Unio), and fossil plant material.