Amy Ray and Emily Saliers--a.k.a. Indigo Girls [ tickets ]--join forces with the Dixie Chicks and Ben Folds for a mid-October benefit gig, which precedes the duo's own headlining tour.

The Honor the Earth benefit takes place on Oct. 10 in Charlotte, NC. Honor the Earth, which will receive all of the net proceeds from the show, is a "national organization that raises funds and public support for Native environmental groups," according to a press release.

Earlier this year, Indigo Girls gave brief acoustic performances during Native American environmental activist Winona LaDuke's Honor the Earth tour, which was billed as a "speaking and performance tour aimed at educating college students and the general public on current issues related to Native environmental activism and the development of wind power on Native lands, in particular."

At the end of October, Ray and Saliers mount a headlining club tour that so far stretches into mid-November; more dates are expected soon. Tickets for most shows hit the box office on Oct. 4 and Oct. 10, according to Indigo Girls' website.

Indigo Girls continue to support "Become You," an album that reached stores nearly a year ago.