Berkey's thesis became the foundational reference for the study of the Dalles of the St. Croix River, a scenic area of 60 square miles on the Minnesota-Wisconsin boundary.
[3][2] During the Catskill Project's nearly two decades of construction, to the mid-1920s, Berkey became, in effect, the country's leading engineering geologist--although that term was not yet in use.
The new field's name came to exist only after the catastrophic failure of the St. Francis Dam in Los Angeles County, California, in 1928 killed more than 400 people.
[3][2] Berkey was Chief Geologist and Petrographer on the Central Asiatic Expeditions of the American Museum of Natural History, famously led by Roy Chapman Andrews in 1922, 1923, and 1925.
Berkey's insistence that the expedition's photographer hike over some hills to record an unusual geological feature led instead to the latter's discovery of the field of fossils that included the famous fossil dinosaur eggs, a find for which Berkey, as a geologist, never claimed credit, later admitting that he "never thought too much about the eggs".