Cottonwood Creek, located on the Kenai Peninsula in Kachemak Bay State Park, flows south for about 2 miles (3.2 km) to the northern shore of Kachemak Bay, about 13 miles (21 km) northeast of Homer and 6 miles (10 km) southwest of Voznesenka, Alaska. The creek was named after the common western black poplar, or cottonwood tree, in 1898 by William H. Dall of the US Coast and Geodetic Survey. Quaternary gravels cover the Kenai Lowlands, except in the Caribou Hills north of Kachemak Bay. Other rock formations are exposed only at sea cliffs and stream beds. The overlying gravels consist partly of glacial deposits, such as till and moraine material, and partly of alluvial sands and gravels. These are largely of glacial origin but were deposited by waters not necessarily glacial. Cottonwood Creek has cut through these sediments, revealing rocks from the Sterling Formation, dating from the Miocene to the Pliocene periods. These rocks are weakly lithified interbedded sandstone, siltstone, mudstone, carbonaceous shale, lignite coal, and minor volcanic ash. The Sterling Formation is up to 10,000 feet (3,050 m) thick. The sea cliffs at the mouth of Cottonwood Creek and canyon expose rocks from the Beluga Formation, which dates to the Miocene. These rocks are similar to those of the Sterling Formation, but the Beluga Formation is only about 5,000 feet (1,525 m) thick. The sea cliff at the mouth of Cottonwood Creek reveals horizontal beds of shale and the remains of a lignite bed about 30 feet (9 m) above high tide level. This bed is 31 feet (9.5 m) thick and burned for 500 feet (152 m) along the bluff. The lignite probably burned many centuries ago. Since thunderstorms are rare in this region, it is possible that climatic conditions have changed, leading to thunderstorms when the lignite bed burned, or that humans who lived on Kachemak Bay after the Pleistocene caused the fire following the glacier’s retreat in Cook Inlet.

Kachemak Bay has attracted human settlement for millennia due to its coastal location, diverse vegetation, relatively mild climate, and abundant wildlife. Archaeological evidence shows that ancestral peoples occupied the area as early as 8,000 years ago. These earliest inhabitants remain unidentified culturally, but archaeologists have recognized three other cultures in the region: Ocean Bay, Arctic Small Tool tradition, and Kachemak tradition. Most early settlers likely arrived by kayaks or larger umiaks from the Kodiak Archipelago, the Alaska Peninsula, Bristol Bay, and later Prince William Sound, as indicated by the materials and tool styles they used. About 1,000 years ago, the Dena’ina Athabascan people migrated into Cook Inlet from the mountains to the west and north of the Kenai Peninsula. Kachemak Bay marked the southernmost extension of Dena’ina territory, where they gathered invertebrates, fished, and hunted marine mammals such as beluga whales, porpoises, and seals. They settled on islands along the southern shore of Kachemak Bay and at sites like Bear Cove, Chugachik, and the mouth of Cottonwood Creek, leaving middens and other habitation evidence. Kachemak Bay has long intrigued archaeologists as an accessible, relatively dry window into the prehistoric past of the Gulf of Alaska. In 1883, Johan Jacobsen tested a village site there and noted a clear separation between two distinct historical cultures. In 1930, Frederica de Laguna began archaeological research in the area, culminating in a monograph on Alaskan prehistory that explored the relationships over time between the Alutiiq people and the Dena’ina Athabaskan cultures. In 1974, William and Karen Workman launched a long-term project in Kachemak Bay, resulting in major excavations at Cottonwood Creek and on Chugachik and Yukon islands. They discovered hundreds of artifacts and several burials, suggesting that Cottonwood Creek’s mouth served as a village site during late winter and early spring when food resources were scarce. Studies of human biology confirmed these were Alutiiq people, who occupied the area for at least 1,500 years, as evidenced by midden remains of shellfish, harbor seals, and porpoises.

In 1970, the Alaska State Legislature designated 105,387 acres (42,650 ha) as Kachemak Bay State Park. Two years later, it added nearly 200,000 acres (80,940 ha) of remote and rugged land and waters to create Kachemak Bay State Wilderness Park. Subsequent land acquisitions have expanded the two areas to about 371,000 acres (150,138 ha). Most of the park is inaccessible by road; visitors typically fly in via air taxi or travel by boat from Homer. However, around 3,000 acres (1,214 ha) of parkland on the north side of Kachemak Bay are accessible by road. These areas include Diamond Creek, Overlook Park, Eveline, and the lands around Cottonwood and Eastland creeks. In 1989, lands in the Cottonwood-Eastland area, accessible from East End Road on Kachemak Bay’s north shore, were added to the state park. In 1995, a purchase of 153 acres (62 ha) increased the total size of the unit to approximately 2,643 acres (1,070 ha), with an estimated 4.9 miles (8 km) of shoreline. In 1993, the Kachemak Bay Critical Habitat Area was established to protect and preserve habitats crucial for sustaining fish and wildlife. In 1999, the Kachemak Bay National Estuarine Research Reserve was established without acquiring new land. It encompasses 372,000 acres (150,543 ha) of terrestrial and marine habitats already designated as either a State Park or Critical Habitat Area. The Reserve extends from the Fox River Flats at the head of the Bay to Point Pogibshi at the southern entrance and Anchor Point at the northern entrance. Read more here and here. Explore more of Cottonwood Creek and Kachemak Bay here: