What: The Indigo Girls, with Lucy Wainwright Roche

When: 7 p.m. Monday

Where: Tower Theatre, 835 NW Wall St., Bend

Cost: $58, $75 plus theater preservation fee

Contact: towertheatre.org or 541-317-0700

It’s pretty much impossible to talk about the Indigo Girls without bringing up the band’s progressive politics.

The Decatur, Georgia, songwriting duo of Amy Ray and Emily Saliers have championed causes such as environmentalism, LGBT rights and Native American rights throughout their three-decade-plus career, playing benefit shows and talking up their activism in the press. Most visibly, Ray and Saliers founded the nonprofit Honor the Earth with Native American activist Winona LaDuke in 1999, working to raise awareness of environmental issues affecting indigenous peoples.

The organization has been heavily involved in the Dakota Access Pipeline protests at Standing Rock. In February, President Donald Trump issued an executive order to restart construction on the pipeline, reversing a previous order from President Obama. In a recent interview with GO! Magazine from her home in Atlanta, Saliers lamented the situation:

“It’s inhumane; it’s beyond description. I mean, there are people there who have been coughing up blood and sleeping in frigid waters and getting hosed down. It’s like the deep South, the way that they treat Indian people up there. The racism is intense. And to have Trump just go ahead and issue that order to totally overlook the environmental impact statement — and to have people getting sick and putting their lives on the line in a peaceful, prayerful (way), (their) only wish to protect water and be on the land that was promised to them by treaty rights anyway — it is the most diabolical thing that’s happened in this country in a long time.”

With the rise of Trump, Saliers and Ray have their work cut out for them. But they also have a plan.

“Part of it is deciding on how to take direct action,” Saliers said. “And we will do that by continuing to do what we’ve always done, which is engage voters and bring groups along (on tour) who can either register people or — we’re working in tandem with groups who are gonna just really get people involved in the political process, with the intent to shift things in the midterm elections (in) 2018.”

Perhaps most importantly, the Indigo Girls will keep singing. The duo kicks off its West Coast tour Thursday with a show with the Oregon Symphony in Portland, and will return to Bend for a performance at the Tower Theatre on Monday.

“I think everybody seems to really be wanting and needing music now,” Saliers said. “We want it in the best and the worst of times, but it’s very, very good for the spirit, the soul, to get together and sing. I also think that art’s gonna have another function, which is to support people who are struggling and to let people out there who are being affected by laws, legislation or administrations know that they’re not alone.”

The rest of the year is looking equally busy for the group. Following this tour, the duo plans to record a symphony record in Colorado in April. The record, which will feature all previously released songs redone with orchestral backing, is a culmination of the shows the Indigo Girls have been performing with orchestras around the country for the last few years.

The duo will also begin work on the proper follow-up to their 16th studio album, 2015’s “One Lost Day,” later this year, Saliers said. “One Lost Day” found the Girls stretching out of their comfort zone with a new producer, Jordan Brooke Hamlin.

Even before that, though, Saliers will finally release her long-awaited solo album “Murmuration Nation” (named for the term for a flock of starlings). Ray has already released five solo studio recordings, most recently 2014’s “Goodnight Tender.”

Saliers describes the 12-track album, produced by Indigo Girls violinist Lyris Hung, as “very rhythmic-centric,” with inspiration drawn from hip-hop artists such as Public Enemy and Queen Latifah, and old-school R&B and soul such as The Jackson 5, Stevie Wonder and James Brown. She’s been playing some of the new songs live with Indigo Girls on this tour.

“It’s a vibe record, I think more so than even an Indigo Girls record,” she said, “which is hard to articulate, but I think mostly because there’s such a focus on the groove of it, and the feeling of the rhythmic things of it. Some of the lyrics are a little less poetic and narrative on some of the songs that deal with the heavier subject matter, and then there are some that are probably what might be considered quintessential Emily ballads that deal with interpersonal relationships.”

But Saliers sounded the most excited about the Indigo Girls’ June tour with folk heavyweights Joan Baez and Mary Chapin Carpenter. The Four Voices tour will reunite these musicians and longtime friends onstage for the first time in more than a decade.

“Joan is kind of coming towards the end of her touring career, so we just — we were trying to think of fun and interesting things to do,” Saliers said. “And her manager approached our management about this idea, and Chapin had been performing with us before, so we thought, well, let’s just do this. We haven’t done it in a long time. It’s out of a lot of respect to Joan and gratitude for her presence on the stage. I mean, she’s a legend.”

Baez, of course, is well known for her political and social activism, and Carpenter in the last decade has also focused on more topical songwriting. With everything going on in the world right now, the timing seems right.

“(Baez) sort of in a way is passing the torch to us and to artists like Chapin who care about what’s going on in this country and the world,” Saliers said. “And so I think in that sense, it’s gonna be a great gathering and a very timely gathering for a group of women artists who, part of our whole reason for being is to be involved in what’s going on politically and socially. And Joan, she’s at the top of that mountain.

“And we’ll have so much fun,” she continued. “They’re just both so smart and funny, and we’re just gonna have so many laughs. So on a personal level, they’re our old friends, and we’re gonna have a great time. And we need fun nowadays.”