Kimball used the band's Twitter account Thursday to announce the news: "Rumors are true! Casey Twist and I are engaged! He's the best!" Kimball's publicist Tree Paine confirmed the report.
Twist also tweeted about the engagement: "I know a certain Cheyenne who is soon to be the future Mrs. Twist. We are engaged! Love that girl!!"
Twist is a singer-songwriter from Siloam Springs, Arkansas.
Gloriana's debut single "Wild at Heart" is R.I.A.A. certified gold, with a half-million copies sold. They won breakthrough artist of the year at the 2009 American Music Awards. Kimball was also featured in her own MTV reality series, "Cheyenne," in 2006.