of Canada's volcanic heritage and how it might impact people in the future. Volcanologists are aware that certain areas in Canada have higher levels of volcanic activity than others and how eruptions in these areas might affect people and the environment they live in. When a volcano is showing evidence of volcanic activity, quick action will be required to better understand the process. The lowest possibility for an eruption in Canada per year is approximately 1/200; for a passive lava eruption the possibility is about 1/220, and for a major explosive eruption it is about 1/3333. Even though volcanoes do not seem to be part of the everyday reality of Canadians, recurrent earthquakes and the formation of large mountain ranges in the Pacific Northwest indicate this part of Canada is still geologically active. The possibility of an eruption, even a large explosive one, cannot be ruled out. Quiet as they currently seem, volcanoes in Northern and Western Canada are part of the Pacific Ring of Fire. Along with volcanoes associated with recent earthquake activity, a scenario of an eruption at Mount Cayley in southwestern British Columbia illustrates how Western Canada is in danger to a volcanic eruption, which has not erupted for at least 310,000 years. This impact is becoming even more likely as population in the Pacific Northwest increases and development spreads. The scenario is based on former eruptions in the north-south trending Garibaldi Volcanic Belt and includes both explosive and passive eruptions. Its effect is mostly due to the attention of defenseless public services in canyons. However, the threat from volcanoes outside of Canada seems much greater than the threat from volcanoes within Canada because of the lack of monitoring data at Canadian volcanoes and the age of most volcanoes in Canada is poorly known. But for some, their minimal degree of erosion indicates they formed much less than 10,000 years ago, including the Milbanke Sound Group on Price Island, Dufferin Island, Swindle Island, Lake Island, and Lady Douglas Island in the Milbanke Sound area of coastal British Columbia. However, it is known volcanoes in the U.S. states of Alaska, Washington, Oregon and California have been more active in historic times than those within Canada. Therefore, volcanoes in the United States are monitored with caution and attention by the United States Geological Survey. Growing awareness of volcanism, especially the threat from volcanoes in the United States, has led