Conodonts from the lowest known horizon of the Wadleigh Limestone, southeastern Alaska, include Polygnathus trigonicus Bischoff and Ziegler, P. angustipennatus Bischoff and Ziegler, P. angusticostatus Wittekindt, P. costatus costatus Klapper, P. pseudofoliatus Wittekindt, P. kockelianus australis Jackson, and P. linguiformis linguiformis Hinde. The fauna is of late Eifelian age. Immediately below this horizon, but with the contact covered by the sea, are thick conglomerates of the Karheen Formation which are thought to be no younger than Emsian. No marine deposits of early or middle Eifelian age have yet been recognized in southeastern Alaska. The presence of thick conglomerates underlying late Eifelian limestones may be evidence of a terrestrial interval possibly resulting from an early Middle Devonian orogeny.