MIRANDA LAMBERT is having her bachelorette party at the Kentucky Derby.  According to Louisville's "The Courier-Journal", Miranda is bringing "a handful of her best gal pals" to the Barnstable Brown Gala.

It's a big time black-tie party going down Friday, May 6th... the night before the Derby. It's a HUGE DEAL.  Other guests include the Jonas Brothers, Run DMC, Nick Lachey, and Joey Fatone of 'N Sync... plus actors and politicians and such.

And it sounds like Miranda and her friends will be staying the whole weekend.  Miranda and BLAKE SHELTON are getting married on May 14th.

(This is just a guess, but I bet Miranda is picking up the tab for this.  It's asking a lot for people to fly to another city and drop loads of cash on hotels and food and "extracurricular activities".  So, with that in mind...)

(What's the coolest out-of-town bachelorette party you've attended that was on someone else's dime?)

(And let's leave Las Vegas out of this.  That's too common.  I want to hear about something creative.)