In 2010, Neyla Pekarek responded to an ad on Craigslist: A little-known band called the Lumineers was looking for a cellist. Pekarek had recently graduated college and moved back home to Denver, and was looking for something to do. She’d also been playing the cello since she was 9. The Lumineers — which consisted then of a singer and guitarist, Wesley Schultz, and a drummer, Jeremiah Fraites — welcomed her.

Pekarek had no idea what was coming: “Ho Hey” rocketing them to fame in 2012, world tours, Grammy nominations. Now, eight years and two albums later, Pekarek is leaving the three-member folk band to pursue her own project.

In 2016 and 2017 alone, Pekarek says, the Lumineers spent something like 600 days on the road. While she’s grateful for the experience, being part of such a “high caliber” band was demanding work. Pekarek didn’t sing much at all for the group, either, which is “probably my favorite thing in the world to do,” she says over the phone, a little bashfully.

Stepping away means that Pekarek is now able to do everything she loves: singing, songwriting, cello-playing. Her debut album, a folk opera called “Rattlesnake,” comes out Jan. 19; its first single, “Train,” is being released to the public Friday.

The album was inspired by another woman’s story: one so mythic and strange and remarkable that Pekarek felt she needed to share it. It’s a story about bravery and grit — which, as she forges her own path, is not at all lost on Pekarek.

The story begins in Colorado in 1925, when the West was not so wild as it once was, but still rough and romantic, a place for adventure-seekers.

It was late October when Katherine McHale Slaughterback, born in 1894, set out hunting. She brought a .22 shotgun, a pony and her 3-year-old adopted son, Ernie, along with her. Kate was a frontierswoman, tough and fiercely independent; she’d built her farmhouse with her own hands.

When Kate arrived at a lake near her homestead, looking for ducks, she found a rattlesnake instead. She shot and killed it, but then she noticed one, two, three more — so she shot those, too. Realizing she had disturbed an entire rattlesnake den — her son perched atop the pony yards away — Kate grabbed a sign and started clubbing them to death. She fought for two hours, she would later tell neighbors and newspapers, and killed 140 snakes. “Rattlesnake Kate” became an overnight sensation.

In 2007, Pekarek stumbled upon the dress Kate made out of those snakeskins at the history museum in the small town of Greeley, Colo., where Pekarek was studying musical theater at the University of Northern Colorado. The dress, reminiscent of a flapper shift with snake tails as tassels, stands in a dark, airtight container; you have to push a button to light it up. Pekarek loved the impossible fragility of the dress, and became “a little obsessed,” she says now, with the story behind it. Most people, even in Colorado, haven’t heard it before.

By late 2015, on tour with the Lumineers, Pekarek was itching for a creative outlet, something of her own. So she started writing songs.

Rattlesnake Kate had stuck with her all those years, too. Still, the first song Pekarek wrote about Kate was a sort of “joke,” she says, meant to entertain her friends.

But once they heard it, her friends told her that she should take the song seriously — that it was good. In what she calls “one of those great moments of creativity,” Pekarek soon wrote two more songs inspired by Kate: “Better Than Annie,” which refers to sharpshooter Annie Oakley, and “Western Woman.”

Then, Pekarek dove deeper, making trips to the Greeley museum to find out all she could about this woman, beyond the rattlesnakes. And what she learned was that Kate was in no way typical of her time: She was married and divorced six times; kept up a 40-year correspondence with a colonel, known as Buckskin Bill, whom she never met; and wore pants, which was uncommon for women.

“I got really inspired by the way she lived completely outside the realm of what was expected of women and outside of the box of femininity,” Pekarek says. “She lived on her own and was really tough. And I think it kind of inspired me to find my own voice and become a little tougher myself.”

Neyla Pekarek. (Liza Nelson)
Neyla Pekarek. (Liza Nelson)

That message, too, was one Pekarek wanted to share with other women. Western history is so “clouded” with men’s stories, she says. She found it ridiculous that Kate’s — not only her rattlesnake encounter, but her entire life story — was virtually unknown.

Pekarek continued to record “Rattlesnake” demos while touring, but writing “Train” was a clear turning point.

The song’s melody came to Pekarek in the car. She was heading to the Denver airport for another Lumineers tour, and Colorado’s grassy plains, the same landscape Kate lived in, spread out before her: a tableaux of the Old West, a vestige of a time when things may have been wilder and rougher, but freer, too. Pekarek sang into her phone all the way through airport security, recording bits of the song as voice memos. The “minute” she got into a room with instruments, she says, she cut a demo.

“This is one of the first songs I wrote that made me feel like I did have something more than a joke,” Pekarek says. It was also the song that helped convince M. Ward, of the indie duo She & Him, to produce the full-length album.

It’s fitting that Pekarek is releasing the first single off of “Rattlesnake” in early November — the same time of year Kate earned her nickname. “Train” is fitting as the first single, too, because the song — which imagines a young Kate setting off on her own — mirrors what’s happening in Pekarek’s own life. “It’s about looking on the optimistic side and feeling there is a new chapter for me as well,” she says.

A few months ago, Pekarek was commissioned by a Denver theater company to turn “Rattlesnake” into a full-fledged musical production. It’s a dream come true, she says, and she’s also performing the songs live as she finishes the album. Pekarek has been learning a lot: mostly, how to be “in charge” as opposed to “being told what to do.”

In “Train,” it’s almost as if Kate and Pekarek have morphed into one. “Just get me on that big tank engine rolling along,” Pekarek sings. “My one-way ticket to a better life and a better song.”

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