| Subarctic America | Alaska, Northwest Territories, Yukon |
| Western Canada | Alberta, British Columbia, Manitoba, Saskatchewan |
| Eastern Canada | Labrador, New Brunswick, Newfoundland, Nova Scotia, Ontario, Prince Edward I., Québec |
| Northwestern U.S.A. | Colorado, Montana, Oregon, Washington |
| North-Central U.S.A. | Illinois, Iowa, Kansas, Minnesota, Missouri, North Dakota, Nebraska, Oklahoma, Wisconsin |
| Northeastern U.S.A. | Connecticut, Indiana, Maine, Massachusetts, Michigan, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia |
| Southwestern U.S.A. | Arizona, California, Utah |
| South-Central U.S.A. | New Mexico |
| Southeastern U.S.A. | Alabama, Arkansas, Delaware, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Tennessee, Virginia, District of Columbia |