Credit: Rick Diamond/ACMA2010/Getty Images for ACMA

It's official: Miranda Lambert is a married woman!

The 27-year-old "House That Built Me" singer wed longtime love Blake Shelton late Saturday evening at Texas' Don Strange Ranch, the couple confirms to Us Weekly exclusively.

Wearing her mother's wedding dress, Lambert walked down the aisle in front of 550 family members and friends (including Reba McEntire, Kelly Clarkson, Martina McBride, Dierks Bentley, Charles Kelly and the Bellamy Brothers).

"I'm married to my best friend!" Lambert told Us after the ceremony. "Looking forward to a lifetime of laughter."

Added Shelton, 34: "I wanted to be married to Miranda the day I proposed. Finally, it's official!"

Dating since 2006, The Voice mentor asked for Lambert's hand in marriage last May. "I fumbled it up a little," he told Us of the proposal. "It's funny how you rehearse those things and go over what you want to say, but I probably screwed it up."

Fortunately, Lambert didn't seem to notice. "He did a really good job," she insisted. "He's always nervous around me, though -- and that's how I like it!"

This is the first marriage for Lambert; Shelton was married to Kaynette Williams from 2003-2006.