Perhaps the dominant feature of the Horsefly River is that it provides some of the most important sockeye salmon and rainbow trout spawning habitat in the Fraser River drainage area. In addition, the river possesses outstanding recreational values because of its scenic and undisturbed qualities. From its origins in the Quesnel Highlands, the Horsefly River flows approximately 98 kilometres through a variety of landscapes. The gradient of the river also varies considerably and includes a ten-metre-high waterfall about 55 kilometres downstream from the river's source.
While a variety of land uses such as agriculture, forestry, and mining are evident along stretches of the Horsefly, significant stretches of the river also provide an atmosphere of wilderness and a rich diversity of wildlife over much of its course. The river's salmon run is an important component of the valley's ecosystem, providing a major food source for a variety of mammals and birds that are typical of the central mountain ranges of BC. At least seven species of fish are supported by the river habitat including rainbow trout, Dolly Varden char, sockeye salmon, chinook salmon, coho salmon, and mountain whitefish.
The river is a critical part of the sockeye salmon run which passes through the Fraser River, making the Horsefly a popular fishing river. Other recreational uses include hunting, hiking, and kayaking/canoeing sections of the river are suitable for paddlers of varying ability. For many years there has been an annual canoe race on the lower Horsefly in late July.
The Horsefly River played an important role in British Columbia's cultural heritage. The area was part of a north-south travel route used by First Nations prior to the arrival of Euro-Canadian settlers and later by all inhabitants of the area. In 1859, the first gold discovery in the upper Cariboo region was on the Horsefly River.
Present economic activity in the Horsefly River drainage area includes logging, mining, ranching, trapping, and recreational resorts. Regional interest groups concerned with the Horsefly River include commercial guides, anglers, canoe clubs, farmers and cattlemen's groups, and First Nation Bands such as Soda Creek, Williams Lake, and Canim Lake. Land use within the area is broadly defined in the Cariboo/Chilcotin Land Use Plan
Proclaimed B.C. Rivers: