On a warm February day in Presidio, Texas, near the Mexico border, Heartless Bastards’ Erika Wennerstrom gears up for another songwriting excursion. “I’ll just go and isolate myself somewhere,” she says. Usually the frontwoman sets up a modest camp (“I’m not like the total primitive type of camper,” she admits. “I don’t do the four-day hike.”) somewhere in the vicinity of her band’s homebase of Austin and adventures through nearby trails to find places where she can think and create. Lately, the words have flowed pretty freely.

“I can say that I’m feeling more inspired than I might have ever been,” she says. “I’m very excited, but you know I’m always excited when I’m writing, but I do feel really great about the things going on right now in my creative process, and hopefully that ends up being something, once it’s done, that people respond to.”

Normally, the process is a little more difficult for the singer, who barely has 2015’s Restless Ones under her belt. “I find writing to be sometimes a real struggle,” she says. “It’s something that I feel the need to do, but actually finishing anything and getting those thoughts complete is such a challenge. But for whatever reason, right now I’m stoked on it. It’s good.”

Titled to describe Wennerstrom’s own character, Restless Ones was written under the Southwest sun, among the canyons of Big Ben’s National Park. While comparisons to the Black Keys are common, Heartless Bastards are their own animal who blend the spirit of late-’60s folk and rock a la the Byrds with Wennerstrom’s rich, deep vocals. She echoes Nico in “Gates of Dawn,” while at other times — “Into the Light,” “Black Cloud” — she wails and the band rocks in ways that harken back to early Kings of Leon.

Wennerstrom says the songs came along after a lot of soul searching. “There’s a lot of self-discovery on there,” she explains. “And I think over the period of five albums with this band, I’ve spent a lot of time really looking forward trying to get somewhere or looking backward. I think that during the process of writing this album, I had to stop and just really appreciate where I am and what I’ve done and just try to be a little bit more in the moment. I think a lot of things were written off-the-cuff on this album — I mean, the ideas were there, but lyrically the songs would just come out and I would go and record them and we’d mix them right then and there.”

Spending less time critiquing each note left Wennerstrom feeling more exposed than ever before. In the past, she’d let things simmer and then evaluate which thoughts she really wanted to put out into the world. “Because when I write, I feel like I’m putting my personal life out there for critique,” she explains. “But [Restless Ones] was in the moment. And I did, I felt vulnerable, but there was also a sense of freedom in letting it all out — and then what happens happens.”

Being so guarded sure didn’t stop the singer from becoming a dynamic force onstage, though Wennerstrom would never admit that she’s exactly that. “I have just always wanted to do this, but I didn’t really start performing until I guess I was about 18 or something — I just didn’t have that much confidence,” she says. “I find myself to be introverted, and the writing part is almost kind of cathartic for me. I think there are two different kinds of performers: There are songwriters who are introverted, and then there are people who very much love the spotlight. And I’m not the person who is really into that. There’s just something that drives me to do what I do.”

But Wennerstrom is now in the throes of coming out of her shell even more. Instead of isolating herself in the woods to compose songs, she’s begun talks with possible collaborators. “I’m definitely open to that,” she says. So how would that work for the self-described introvert? “I think in that sense, it’s almost like you can write from the idea of telling a story and kind of create this story with this other person and balance ideas off each other,” she says. “I think there’s a way to make it not totally generic, because I do think it’s important to be personal. I think sincerity is something a lot of people feel as a listener.”

She continues, “Maybe I’m wrong, but I guess I never want to write some kind of generic love song with someone, you know? Maybe that’s being closed-minded — it’s just until I really get in there, it’s going to be tough to know what comes out of it. Maybe there’s the most amazing song out there —maybe there is a love song I could write with somebody. I don’t know — I guess we’ll see what happens.”