Tweedsmuir Provincial Park was established May 21, 1938. The park was named for the 15th Governor General of Canada, John Buchan, Baron Tweedsmuir of Elsfield. The Governor General traveled extensively by float plane and horseback in the park during August of 1937 and he and his party were greatly impressed by its magnificence.
Eutsuk Lake, located within the park, derives its name from the Ulkatcho Carrier dialect and is the focal point of the water-oriented activities of North Tweedsmuir Park. A number of waterways owe their names to Father Adrien Gabriel Morice, who surveyed the area in the late 19th century producing accurate, detailed maps.
The northern section of Tweedsmuir Park is almost entirely pristine wilderness. The lake-and-waterway-dotted Nechako Plateau, a division of the vast Interior Plateau, forms most of the northern region with the Quanchus Mountain Range, dominated by Mount Wells and Tweedsmuir, Michel, Wells Gray and Eutsuk Peaks, all more than 1900 metres in height, covering much of its central area. Lower elevations are forested for the most part with lodgepole pine mixed with some white spruce. Mountain slopes to the timberline, at approximately 1525 metre elevation, are covered with subalpine (balsam) fir and Engelmann spruce. Interspersed throughout are natural grass clearings and black spruce dominated boggy areas.
Wildlife is widespread and fairly prevalent. In summer and fall woodland caribou frequent the slopes of the Quanchus and Chikamin Mountain Ranges. In other areas mountain goats, mule deer, moose, black bear, grizzly bear and wolves are in evidence.
Visitors to the alpine meadows often see smaller mammals such as hoary marmots, wolverines, and Siberian lemmings as well as various bird species, including willow ptarmigans, gray-crowned rosy finches and golden-crowned sparrows.
Elsewhere members of the grouse family occur in considerable numbers and waterfowl are usually plentiful in the swamps and ponds. Around the Nechako Reservoir, dead trees provide nesting sites for fish-hunting ospreys.