Bumble Bee identification help

[olivier]

I live in north western Washington state and have taken an interest in bees here. I see bumble bees that look like Black-tailed Bumble Bees or Yellow-Fronted Bumble Bees and I cant tell the difference for each other by looking at photos on Inaturalist.

Is there any physical characteristic I can use to distinguish the two?

[akcolias]

www.mtent.org/projects/Bumble_Bees/key_female.html

[olivier]

Thank you!

[alandmor]

You may find these of interest.

extension.oregonstate.edu/bee-atlas

www.oregonbeeproject.org/