Western Bumble Bee

Historically broadly distributed in western North America. Bombus occidentalis occurs along the Pacific coast and western interior of North America, from Arizona, New Mexico and California, north through the Pacific Northwest and into Alaska. Eastward, the distribution stretches to the northwestern Great Plains and southern Saskatchewan.  

Bombus occidentalis - Wikipedia

Western bumblebee populations suffering alarming declines, study

Good News for the Western Bumble Bee, Bombus occidentalis

Early emerging bumble bee species to look out for this spring

Yellow-banded Bumble Bee Vermont Center for Ecostudies

Western Bumble Bee (Bombus occidentalis) Once common, now

UW researchers publish on the decline of the Western bumblebee

Colorado's western bumble bee population in rapid decline, future looks grim

Western Bumble Bee - Montana Field Guide

Study: Keystone Western bumblebee is in trouble

Bumble Bees of the Western United States

Western Bumble Bee? - Bombus occidentalis