Simpson in 1828. More Europeans entered the Thompson River valley in the early to mid 1800s, drawn by the fur trade and small gold rushes. Others started farming on the fertile benches of the river, and a North West Company trading fort at the confluence of the North and South rivers became the city of Kamloops, now the largest human population center in the watershed. Ecology The Thompson River supports 24 fish species, including two considered endangered. It also hosts carp, which are not native to the watershed. The river is home to large populations of Pacific salmon, including coho, sockeye, pink and chinook. Through its tributary, the Adams River, the Thompson has one of the largest sockeye salmon runs in the world. Pink salmon spawn mostly below Kamloops Lake, while coho spawning beds are found in 40 of the Thompson watershed's streams and rivers. Coastal rainbow trout (Oncorhynchus mykiss irideus), including an anadromous variety called steelhead, are found in the river along with a local strain the Kamloops rainbow trout which occurs in Kamloops Lake at the Thompson River headwaters and other nearby lakes. Other fish species include round whitefish, largescale sucker, bridgelip sucker, northern pikeminnow, longnose dace, and slimy sculpin. Several bird species are found in Thompson River environments, including osprey, merganser, wood ducks, and American dippers. Golden eagles are found near the confluence with the Fraser, and Bald eagles congregate on the river during the salmon run. Trumpeter swans use the South Thompson on their migratory route. Rattlesnakes are found in the dry sagebrush regions of the lower river. Aquatic insects found in the river system are dominated by three groups: mayflies, midges, and caddisflies. Many of these species emerge with the spring snowmelt, which greatly increases the volume of flow on the river. Conservation and recreation The Thompson River and its two branches are mostly unprotected through parks or reserves. Small sections of the river are within provincial parks, including Steelhead, Juniper, Goldpan, and North Thompson Provincial Parks. Some of its tributaries, such as the Clearwater, are more protected through large parks like Wells Gray. However, unlike major river systems to the north and east like the Columbia and Nechako, the Thompson has no hydroelectric dams or major man-made water diversions. Under the British Columbia Fish Protection Act of 1997, the Thompson cannot be considered for future dam construction. Conservation of the Thompson's fisheries, especially its