Nordyke Island is about 35 feet (11 m) high, flat-topped and grass-covered, and located in Kamishak Bay, about 115 miles (186 km) northwest of Kodiak and 96 miles (155 km) southwest of Homer, Alaska. Two smaller flat, grass-topped islands lie southwest of Nordyke Island, and a series of reefs and rock ledges are exposed at low tide between Nordyke Island and McNeil Head on the southern shore of Kamishak Bay. The island was first mentioned in a report on Kamishak Bay by Kirtley F. Mather, published in 1927 by the US Geological Survey. Nordyke Island and most of Kamishak Bay are underlain by sedimentary rocks at least 6,000 feet (1,829 m) thick, represented by the Naknek Formation, which consists of sandstone, conglomerate, and siltstone. This rock unit is widespread in southern Alaska, ranging from Southcentral Alaska to the southwest end of the Alaska Peninsula, including the northwestern flank of the Aleutian Range in Katmai National Park and Preserve. These rocks are exposed at low tide as wave-cut platforms extending up to 2 miles (3.2 km) from shore. Macrofossils, particularly the pelecypod Buchia, are common, and the fauna, which also includes ammonites, indicates a Late Jurassic age of about 161 to 146 million years ago.

Kamishak Bay is a broad indentation at the northern end of the Alaska Peninsula, about 20 miles (32 km) northwest of Cape Douglas near the mouth of Cook Inlet. The bay has numerous reefs rising to within a few feet of the surface that, combined with a tidal range of over 24 feet (7.3 m), make navigation hazardous. Winds in Cook Inlet are largely driven by the strength and position of the Aleutian Low and the surrounding mountainous terrain. In winter, winds are generally from the north and northeast; in summer they are more often from the south and southwest, driven in part by the temperature gradient between land and ocean. During strong northwest to west winds, common after mid-August, the bay experiences amplified winds due to the funnel effect of the Aleutian Range to the west. These topographic gap winds are often accompanied by short, high, choppy seas on flooding currents, creating dangerous conditions for small vessels. Kamishak Bay is shallow and larger vessels generally stay within charted channels, although there is a good anchorage in the lee of Nordyke Island.

The southern portion of Kamishak Bay is the traditional territory of the Central Yup’ik people; the portion north of Augustine Volcano is Dena’ina territory. Villagers from Iliamna Lake, and sometimes people from as far west as Togiak in Bristol Bay, historically came to Kamishak Bay to hunt sea otters and possibly other marine mammals, such as beluga whales, from seasonal camps at Amakdedori and Chenik. In 1880 Ivan Petrof conducted a census recording a village called Ashivak on Kamishak Bay near the mouth of the Kamishak River, likely an Alutiiq sea otter hunting camp serving the trading post at Douglas. Pacific herring were first commercially harvested in lower Cook Inlet in 1914, but spotter pilots and pioneering fishermen did not locate and exploit herring in Kamishak Bay until 1973. Frequent storms, treacherous reefs, and the area’s relative remoteness explain the fishery’s late development and the challenges of assessing and managing it. In 1973 the herring sac roe fishery yielded 243 short tons among 8 permit holders; by 1976 it had grown to nearly 4,400 tons landed by 66 permit holders. The following year a limited entry of 73 permits was established to control further expansion. Harvests then declined sharply, from 4,393 tons in 1976 to 376 tons in 1979, and the fishery was closed from 1980 through 1984 to allow stock rebuilding. It reopened from 1985 to 1998 with an average annual harvest of 2,878 tons before closing again after the 1998 season due to low abundance. Read more here and here. Explore more of Nordyke Island and Kamishak Bay here: