Although the monarch butterfly has been recorded in all ten Canadian provinces and the Northwest Territories, there are two very distinct populations in North America — one in the East and one in the West. The western population includes monarchs west of the Rockies that winter in tree groves on the coast of California. The larger eastern population occurs east of the Rockies, from southern Canada down to the Gulf Coast of the United States. It winters in central Mexico.
© 2010, Royal Canadian Geographical Society. All Rights Reserved.