[4] It lives only in a 190-by-70-mile (310 by 110 km) area in southern Oregon and northern California, between the Coast and Sierra-Cascade mountain ranges.

[1] Franklin's bumblebee is a generalist forager which collects nectar and pollen from several wildflowers, such as lupine, California poppy, and horsemint.

[citation needed] Some experts, such as professor Dave Goulson at the University of Sussex,[8] say this species is already extinct, but until more concrete evidence is shown, it has been assigned a conservation status rank of G1 (critically imperiled) by NatureServe,[2] and categorized as critically endangered by the IUCN Red List.

[1] A petition was submitted by the Xerces Society, Defenders of Wildlife, and the Center for Food Safety to the California Fish and Game Commission in October 2018 to list Bombus franklini and three others as endangered under the California Endangered Species Act.

[11] A subsequent legal challenge of the CESA's definition of a fish as "a wild fish, mollusk, crustacean, invertebrate, amphibian, or part, spawn, or ovum of any of those animals"[11] was eventually overruled, because the explicit intent was for all invertebrates (therefore including insects) to be qualified for protection under this legal definition.