Potassium–argon dates and chemical data have been obtained from three mid-Tertiary volcanic centres in the Hope area of the Cascade Mountains, southwestern British Columbia. Two of these, the Coquihalla volcanic centre and the Podunk Creek body, prove to be of early Miocene age (ca. 22 Ma), whereas the Skagit Formation is mid- to late Miocene (ca. 12.5 Ma). All three bodies are calc-alkaline.