The Sinkiuses may have come either from the lower Columbia River area or from a more northerly location. They encountered non-Indians and joined the fur trade in 1811. They fought the United States in the 1850s under their chief, Moses, but adopted a peaceful stance after the war. The Columbia Reservation was established in 1879 and was abolished several years later. Four bands followed Chief Moses to the Colville Reservation; others accepted allotments and lost their geographic identity.
Autonomous villages were each led by a chief and a subchief; these lifetime offices were hereditary in theory but were generally filled by people possessing the qualities of honesty, integrity, and diplomacy. The authority of chiefs was granted mainly through consensus.
An informal assembly of all married adults confirmed a new chief and oversaw other aspects of village life. All residents of the village were considered citizens. Other village leaders included a messenger, a speaker, and a salmon chief (often a shaman, with the salmon as a guardian spirit, who supervised salmon-related activities). By virtue of their ability to help or hurt people, shamans also acquired relative wealth and power from their close association with chiefs, who liked to keep them allied.
The Sinkiuses were seminomadic for nine months a year; during the other three they lived in permanent wintertime villages. Winter was a time for visits and ceremonies. During that season, women also made mats and baskets, made or repaired clothing, and prepared meals; men occasionally hunted or just slept, gambled, and socialized.
In spring, groups of four or five families left the village for root-digging areas; those who had spent the winter away from the main village returned. People rose at dawn, in the winter and summer, and began the day by bathing in the river. The men's realm was toolmaking, war, hunting, fishing, and, later, horses.
Pacifism, generosity, and interpersonal equality and autonomy were highly valued. Girls fasted and were secluded for ten days at the onset of puberty, except for a nighttime running regime. The exchange of gifts between families constituted a marriage, a relationship that was generally stable and permanent.
The Sinkiuses built typical Plateau-style, semi-excavated, cone-shaped wood-frame houses covered with woven matting and/or grass. Longer, lodge-style structures of similar construction were used for communal activities. Villages also contained mat-covered sweat lodges. Temporary brush shelters served as summer houses. Later, skin teepees replaced the aboriginal structures.
They also built communal tule-mat houses consisting of a pole framework covered by grass, earth, and tule mats. These houses were about sixteen feet wide, between twenty-four to sixty feet long, and about fourteen feet high, with gabled roofs. Entry was through matted doors. Each family had an individual tule-covered section, but they shared a number of fireplaces in the central passage.
Food was much more often acquired by the family than by the village. Fish was a staple. Men caught four varieties of salmon as well as trout, sturgeon, and other fish. They fished from May through October. Women cleaned, dried, and stored the fish. Dried fish and sometimes other foods made up much of the winter diet. People generally ate two meals a day in the summer and one in the winter.
Women gathered shellfish, salmon eggs, bulbs, roots, nuts, seeds, and berries. Camas was eaten raw, roasted, boiled, and made into cakes. A short ceremony was performed over the first gathered crop of the season. Men hunted most large and small game in the fall. They prepared for the hunt by sweating and singing. Women came along to help dress and carry the game. Men also hunted birds and gathered mollusks.
Men caught fish with nets, weirs, traps, and hook and line. Utensils were carved of wood. Women made coiled baskets of birchbark and/or cedar root; they also wove wallets and bags of woven strips of skin, and they sewed tule mats and other items.