Magnetic Island is a small island on the north side of Tuxedni Bay, an inlet on the lower west side of Cook Inlet in south-central Alaska. The island is surrounded by mudflats that are under water during high tides. The island got its name from the presence of magnetism (believed due to magnetite) identified during a geological survey in 1951. Its shape and geology are heavily influenced by Mount Redoubt and Mount Iliamna, two active volcanoes located less than away.