What it is
Franklin’s bumble bee (Bombus franklini) is a bumble bee with one of the smallest ranges of any Bombus: a sliver of southern Oregon and northern California. IUCN lists it as Critically Endangered. Surveys from the 1990s into the 2000s documented a collapse.
Range
A short stretch of the Klamath-Siskiyou region, historically from southern Oregon into northern California. It was never a continent-wide bee.
What happened
Once locally familiar to specialists, it became vanishingly rare within about a decade. Disease spillover from managed bees, habitat loss, and a small range are the usual suspects; the last widely accepted records are sparse. The range was always a short Oregon-California sliver: not a stand-in for every declining Bombus.
When / status
Critically Endangered now. Range always tiny; numbers collapsed recently.
Human role
A small endemic range plus the pressures people added: pathogens, farms, and a changed landscape.
Sources
IUCN Red List (Bombus franklini, CR).