This is a wild-ass guess—these look more like wasps than bees to my eye—but these are beautiful insects.
Hoping that tagging a genus will help the right folks see this (and either reclassify correctly or narrow down further).
on Gaillardia - Blanket Flower
On Camassia quamash at Rocky Prairie Natural Area Preserve
B. flavifrons or B. mixtus?
B. flavifrons or B. mixtus?
Two similar bumble bees were pollinating the Yellow Sand Verbena. They had cream-colored non-fuzzy faces. This one was paler than the other.