The Garibaldi Volcanic Belt is the northern extension of the Cascades Volcanic Belt in the northwestern United States (including Mt. Baker and Mt. St. Helens), and contains the most explosive young volcanoes in Canada. It's volcanoes are also the closest to British Columbia's densely populated southwest corner. These volcanic belts are the result of subduction of the Juan de Fuca tectonic plate beneath the North American tectonic plate; the plates meet just seaward of the west coast of Vancouver island. The volcanoes of the Garibaldi Volcanic Belt generally are stratovolcanoes typical of subduction zone volcanoes, and include Mt. Garibaldi, Mt. Price, the Black Tusk, Mt. Cayley, Mt. Fee, Mt. Meager and Mt. Silverthrone.

Mt. Meager's eruption of 2350 years ago is the youngest explosive eruption in Canada. It was similar to that of Mt. St. Helens in 1980 and also the ongoing eruption of Montserrat in the Caribbean. The explosive phase of this eruption generated an ash plume that covered most of southern B.C. and extended into southern Alberta. The existence of anomalous heat beneath Mt. Meager is demonstrated by the large number of hotsprings around the volcano, some of which feed the hot tubs at Meager hotsprings.