Hi Dale...
I live on the east coast, and in my state alone (CT) there are at least 4 big bands that I know of. These are essentially "rehearsel" bands that run charts/arrangements on a weekly basis, and then play the ocassional gig. There doesn't seem to be a lack of players to fill all the section chairs as big band jazz is pretty popular here... who knows... could be the close proximity to ALL the music colleges in this area: Berklee, Hartt, Eastman, etc... As a matter of fact...

Buddy Rich drew heavily from Berklee in Boston to staff his band...! Also...

One band in particular here in CT plays a decent amount of BR arrangements. A friend of mine, an alto sax player, likes to play with this band as he enjoys the challenge of the Rich library... I ended up doing a few gigs with a couple of the big bands here... I filled in for the regular drummer, so much of my time was spent reading down the charts... was still fun, although I would have enjoyed it a lot more if I didn't have my head buried in the arrangement!

Perhaps YOU should start one in your area! That would be a neat undertaking!