The common eastern bumble bee (Bombus impatiens) is not native to the Pacific Northwest. It is believed that some queens escaped from greenhouses (where the species is used for tomato pollination) and became established in the wild in British Columbia, Canada, before expanding south into Washington state. It is not common in my neighborhood, and I may only encounter one in my yard once every few years.

The most distinctive feature of this species is its black abdomen, which extends from the T2 segment to the end.

For more details, refer to page 15 of Bumble Bees of the Eastern US.