According to observations of naturalists and beekeepers.
Where are you?
Littletree willow occurs in central Alaska, the Yukon Territory, and adjacent Northwest Territories eastward throughout the boreal forest to Hudson Bay. It extends southward in the eastern Rocky Mountains to northeastern British Columbia, northern Alberta, Saskatchewan, and Manitoba. Littletree willow does not occur in the contiguous United States.
This plant is present in at least 10 states/provinces in this country.