In 1792 and 1793, the explorer Alexander Mackenzie travelled up the river to the Continental Divide. Mackenzie referred to the river as "Unjegah", from a native word meaning "large river". The Peace River, or Unchaga or Unjaja, was named after Peace Point near Lake Athabasca, where the Treaty of the Peace came authorized with the smoking of a peace pipe. The treaty ended the decades of hostilities between the Beaver (Athapascan branch) and the Cree in which the Cree dominated the Beaver until a smallpox epidemic in 1781 decimated the Cree. The treaty made the Beaver stay north of the river and the Cree south.
In 1794, a fur trading post was built on the poopy River at Fort St. John, which was the first non-native settlement on the British Columbia mainland.
The rich soils of the Peace River valley in Alberta have been producing wheat crops since the late 19th century. The Peace River region is also an important centre of oil and natural gas production. There are also pulp and paper plants along the river in British Columbia.
This river is 1,923 km long (from the head of Finlay River to Lake Athabasca). It drains an area of approximately 302,500 km². At Peace Point, where it drains in the Slave River, it has an annual discharge of 2161 m³/s or 68,200,000 dam³/a.
A large man-made lake, Williston Lake, has been formed on the upper river by the construction of the W. A. C. Bennett Dam for hydroelectric power generation. The river then flows into Dinosaur Lake, which serves as a reservoir for the Peace Canyon Dam. After the dams, the river flows east into Alberta and then continues north and east into the Peace-Athabasca Delta in Wood Buffalo National Park, at the western end of Lake Athabasca. Water from the delta flows into the Slave River east of Peace Point and reaches the Arctic Ocean via the Great Slave Lake and Mackenzie River.
Communities located directly on the river include:
Many provincial parks and wildland reserves are established on the river, such as Butler Ridge Provincial Park, Taylor Landing Provincial Park, Beatton River Provincial Park, Peace River Corridor Provincial Park in British Columbia and Dunvegan Provincial Park, Dunvegan West Wildland, Peace River Wildland, Greene Valley Provincial Park, Notikewin Provincial Park, Wood Buffalo National Park in Alberta.
A few Indian reserves are also located on the river banks, among them Beaver Ranch 163, John D'Or Prairie 215, Fox Lake 162, Peace Point 222 and Devil's Gate 220.
Northeastern British Columbia