On Seward Peninsula, extends into Kotzebue Sound, 42 mi NW of Deering, Kotzebur-Kobuk Low.
Named in 1816 by Lt.Otto von Kotzebue (1821, p. 236) for Dr. Karl Espenberg, a surgeon who accompanied Captain (later Admiral, Imperial Russian Navy (IRN)) Adam Johann von Krusenstern on his voyage around the word in 1803-06.