Muskeg [Algonquian, "grassy bog"] is a term describing a type of landscape, environment, vegetation and deposit. It attained widespread use in the 1950s during northward expansion of resource development. Peatland and organic terrain are equivalent terms generally referring to northern landscapes characterized by a wet environment and vegetation (eg, black spruce muskeg) botanically classified as mire (subdivided into bogs and fens).

Muskeg defies precise scientific definition. It may cover large areas (Hudson Bay Lowland) or occur as small, isolated pockets. Muskeg produces peat deposits of variable thicknesses and types because of incomplete decomposition of plant matter in the wet, acid environment. The particular vegetation and hydrological patterns allow recognition of different muskeg types by remote sensing. Most peat and muskeg in Canada is less than 10 000 years old and occurs in areas covered by the last glaciation. Peat accumulation rates and the distribution of muskeg are dependent on climate conditions and controlled by climate changes. In northern regions, muskeg and permafrost are closely associated and can present difficult engineering problems. No comprehensive, Canada-wide survey of muskeg has been made, but various estimates indicate that Canada may have more muskeg (over 1 295 000 km2) than any other country.

Because of its importance to wildlife, water resources and the northern environment, muskeg is no longer considered wasteland. When managed properly, organic soils on peat have excellent capability for agriculture and forestry. Peat products have long-established uses in horticulture, and there is renewed interest in peat as an alternate energy source. Peat provides raw materials for the chemical industry (resins, waxes, paints, etc) and can serve as an efficient filter for some hazardous wastes.

See also Swamp, Marsh and Bog; Vegetation Regions.