The Waskesiu upland includes the upper elevations of Prince Albert National Park as well as the upland area north of the park known as the Thunder Hills. Elevations range from 550 m at the base of the upland to over 750 m. The system of external drainage consists mainly of streams that originate in the upland and, controlled by its relief, drain downslope to the adjacent lowlands. The upland in the southern part drains to the south via the Sturgeon and Spruce rivers, which empty into the North Saskatchewan River near Prince Albert. The remainder of the upland drains eastward into Montreal Lake and then northward into the Churchill River system via the Montreal River.
Like most major uplands in the province, the landscape is primarily a plain composed of unstratified clay and stones (till) deposited by glaciers. At the upper elevations the landscapes are gently undulating to moderately rolling, although those in the northern part are generally rougher and have steeper slopes than those in the south. Surficial sediments are comprised mainly of loamy textured glacial till, although clayey sediments, derived from erosion of the surrounding uplands during deglaciation, occur sporadically in the southern regions. In most instances, the small, rounded hills (knolls) and upper slopes are comprised of glacial till, with the clayey stratified sediments overlying the till on the lower slopes. Sediments derived from glacial lakes (glaciolacustrine) are rare in the northern part of the upland, but shallow sandy materials are commonly found overlying the till on the lower slopes. As usual in these types of landscapes, the depressional areas are filled with organic materials. Steeply sloping cliffs or escarpments dissected by numerous large, deep-set valleys occur in the southern part of the upland. Many have relatively small streams, called “misfit streams,” indicating the valleys were likely former channels formed by the passage of water melting from glaciers. Areas of sandy and gravelly sediment are often found at the base of the escarpment. The steeply sloping escarpments, in contrast to the upper plateau-like tops of the uplands, are almost devoid of wetlands except along the small creeks themselves.
Mixed stands of trembling aspen and white spruce are dominant on the well-drained sites in the southern part of the upland. In the northern part of Prince Albert National Park and to the south in the Thunder Hills, coniferous stands of jack pine and black spruce are by far the most prevalent. Black spruce and tamarack are, as expected, the dominant tree species on the poorly drained peatlands.
Merle Massie