by archaeologist J. Louis Giddings in the late 1940s found campsites on the cape as much as 4,000 years old, and even older sites on the mainland. University of Washington researchers have undertaken several years of excavations to document about one third of the beach complex. Researchers found campsites, hearths and animal bones, with a few stone tools and pieces of pottery. In newer locations the team documented the remains of semi-subterranean houses built into the beach ridges, such as the Old Whaling site. The oldest mainland sites such as Battle Rock, Rabbit Mountain and the Lower Bench date to the Paleo-Arctic tradition, about 10,000 to 7,000 years before present. Similar materials have been recovered in the Trail Creek caves of Bering Land Bridge National Preserve on the Seward Peninsula. The Palisades site has yielded materials from the Northern Archaic period dating to about 6,000 years before the present. Later periods described in the region include the Arctic Small Tool tradition and the Northern Maritime tradition. The western Thule culture, which used dogs and seal oil extended from 950 AD to 1400, and was succeeded by the Kotzebue culture from about 1400 to about 1850, when Europeans began to affect native cultures. Kotzebue sites are widespread within the monument. Later history Europeans visited the Cape Krusenstern region to pursue whales beginning in the 1850s. During the American Civil War the Confederate raider CSS Shenandoah captured whalers in the area. In early modern times the Kotzebue area was the site of Qatnut, a kind of trade fair for the region's native people. Qatnut is still celebrated in modern times in the city of Kotzebue, Alaska every other summer. A short-lived gold rush brought prospectors to the Seward Peninsula and Kotzebue in the 1890s. A few 20th century structures exist in the monument, including an Alaska Road Commission cabin at Anigaaq that has been evaluated for historic significance. In the 1950s the area's lack of good natural harbors, a desire to develop the Alaskan frontier facing the Soviet Union and the Operation Plowshare drive for the peaceful use of nuclear weapons brought proposals for Operation Chariot, a proposed deepwater harbor at Cape Thompson northwest of the monument, to be excavated using nuclear devices. The project, though popular elsewhere in Alaska, was opposed by native leaders and was discarded. Ecology and environment The lands within the monument, which lies entirely above the Arctic