In 1926, Clark began a major project to map the geology of the Quebec Appalachian Mountains along the U.S. border in the Eastern Townships. He published a series of papers on the geology and paleontology of the Townships.
In 1926, Clark launched a comprehensive study to map the geology of the Quebec Appalachian Mountains along the U.S.-Canada border in the Eastern Townships. He subsequently shared his findings through a series of papers on the region's geological history and paleontology.