This may be Bombus menaopygus (Orange-Rumped Bumble Bee). It’s also possible that it’s the Tri-Coloured Bumble Bee, Bombus ternarius. I didn’t get close enough to examine all the subtleties.*
(I find myself unreasonably delighted that the genus name is “Bombus.”)
At any rate, she** was on our gravel drive not far from where Our Dog was basking. I took some pictures. She didn’t respond, so I wasn’t sure whether she was healthy or not. Either way, the drive wasn’t a good place to be, so I got a twig and started to slide it under to move her.
Well, I guess she was quite healthy after all. I’m glad bumblebees aren’t aggressive.
At any rate… doesn’t she look all soft and pettable?
** How do I know she’s a she? Well, I found this explanation… and look, yes, pollen basket.