U.S. Rep. Lauren Boebert drew another Democratic challenger in Colorado’s 3rd Congressional District.

Grand Junction Mayor Anna Stout on Wednesday filed paperwork to run for the seat in what’s shaping up to be the most expensive contest on next year’s state ballot.

Stout’s primary opponents include former Aspen City Councilman Adam Frisch, who came within fewer than 600 votes of unseating the Silt Republican in 2022 and has posted record-breaking fundraising totals this year.

Boebert, an outspoken gun rights advocate and former restaurant owner, is seeking a third term next year in the sprawling, Republican-leaning district, which covers most of the Western Slope and parts of southern Colorado, including Pueblo County and the San Luis Valley.

Election forecasters at the Cook Political Report last week shifted the district to toss-up status from “Lean Republican,” citing Frisch’s lopsided fundraising advantage, including raising more than three times what the incumbent collected in the most recent quarter.

“It’s no secret that Lauren Boebert has repeatedly failed to represent our values in Congress, and her only accomplishment has been making a name for herself as a member of the most extreme faction of her party,” Stout said in a statement. “Colorado’s 3rd congressional district deserves better.”

Added Stout: “As the mayor of my hometown, the largest city in Western Colorado, I have a record of bringing people together to get things done and listening to the people I represent. I will take that same work ethic to Congress and build on my record of delivering real results for the hardworking people of our district.”

Stout was reelected this spring to a second term on the nonpartisan Grand Junction City Council, whose members elected her to serve as mayor.

A certified animal welfare administrator, Stout is the CEO of the Roice-Hurst Humane Society. She founded and serves as president of the nonprofit Foundation for Cultural Exchange, which facilitates the relationship between Grand Junction and its sister city, El Espino, in El Salvador. She’s also a certified court interpreter and Spanish translator.

Stout’s campaign manager told Colorado Politics that she plans to launch her campaign formally on Aug. 1.

Boebert’s campaign didn’t respond to a request for comment, but a spokeswoman for the National Republican Congressional Committee predicted in a statement that Stout and Frisch will “battle it out for who can go the farthest to the left,” while Republicans focus on the district’s needs.

“It doesn’t matter who gets the Democrat nomination, they will be left broke, bruised and unpalatable for general election voters,” added NRCC spokeswoman Delanie Bomar.

Frisch, who has been crisscrossing the district since announcing his bid for a rematch in February, said in a statement that its constituents deserve “a representative who is focused on building community, not chaos.” He added: “I am confident that my proven track record of building consensus and offering common sense solutions puts us on track to win in November 2024.”

Other Democrats in the race include Gunnison veterinarian Debby Burnett, who ran last cycle but failed to make the primary, and first-time candidates David Karpas and Adam Withrow.