Yukon Island is an island in outer Kachemak Bay, an inlet of the Cook Inlet of south central Alaska. The island is located about 9 miles (14 km) south of Homer. The island is archaeologically sensitive, with a number of sites documenting the prehistory of the bay. The Yukon Island Main Site, a National Historic Landmark, is a major shell midden site at which the pioneering archaeologist Frederica de Laguna was able to sequence 1500 years of the area's prehistory, and other sites have been found on the island since then.