The earliest human use of the land was by the Coastal Native peoples of British Columbia, who, by travelling the route of the present-day Skyline Trail, accessed the Upper Similkameen Valley. The first European in the area was 1813 and was explored and mapped in 1827 by Archibald McDonald. Access to the area prior to the
Great Depression was extremely limited for the lack of any kind of developed roads or trails over the Cascade Mountains other than the
Dewdney Trail, far to the north. The earliest form of the park was established in 1931 as the Three Brothers Mountain Reserve to prevent
overgrazing, and it eventually became the Three Brothers Game Reserve in 1936. In 1941, the park was formed as Three Brothers Mountain Park, a Class A Provincial Park. In 1929, the construction of a road through the area was begun as a work project for the unemployed, but it did not get completed. When the Canadian government began to
intern Japanese Canadians after the
Attack on Pearl Harbor, one camp was formed in the present-day
Sunshine Valley, and the workers built the current Hope-Princeton highway, which was completed in 1949. The current route of the Hope-Princeton highway follows the route of the
Allison Pass Trail, which was constructed in 1859–1860. During the completion of the highway, great emphasis was put on the relatively new concept of the motoring family. The Parks Branch worked to great lengths to ensure the aesthetic quality of the vistas along the highway were maintained. The park was named in memory of Ernest Callaway Manning, Chief
Forester of British Columbia from 1936 to 1941 (not to be confused with
Ernest Charles Manning, Premier of
Alberta from 1943 to 1968). Manning was killed in an airplane accident in 1941. During his time as Chief Forester, he was instrumental in developing the idea of setting land aside for future generations to enjoy. It was the teamwork of Manning and
Arthur Wellesley Gray, Minister of Lands from 1933 to 1944, that established
Tweedsmuir Provincial Park,
Hamber Provincial Park,
Wells Gray Provincial Park, and E.C. Manning Provincial Park. Over the years, Manning Park has decreased in size, the most noticeable change being the park boundary in the east. Originally, the park included Similkameen Falls, but mine claims and private land ownership have since caused the boundaries to move more than west. While the park's ecology and ecosystems remain relatively intact, logging has occurred numerous times throughout the park's history, as parks historically focused more on the visual qualities for the public rather than ecological conservation. == Geography ==