Democratic congressional candidate Diane Mitsch Bush has been endorsed by former Interior Secretary Ken Salazar, whose brother John Salazar was unseated by U.S. Rep. Scott Tipton, the Republican incumbent Mitsch Bush is challenging, her campaign announced Thursday.

Mitsch Bush, a former state lawmaker and Routt County commissioner from Steamboat Springs, is one of three Democrats running in a primary in the sprawling 3rd Congressional District. The others are Glenwood Springs municipal and water attorney Karl Hanlon and former Eagle County Commissioner Arn Menconi, the 2016 Green Party nominee for the U.S. Senate.

“Diane has gained a reputation, through her strong record, as a champion for the causes that matter most to us in the 3rd Congressional District,” Salazar said in a statement. “Whether she is dealing with water, jobs and the economy, public lands, agriculture, or transportation, Diane brings people of all political stripes to the table for common sense legislation that benefits her constituents. Only a person with Diane’s broad appeal and legislative experience can win back this seat for the people of CD3. I proudly endorse her.”

Mitsch Bush said she’s known Salazar, a former attorney general and U.S. senator, since her first campaign for county commissioner a decade ago. “I have learned so much about what it takes to bring people to the table and find common ground from Ken,” she said in a statement.

The 3rd CD covers the Western Slope, Pueblo County and the San Luis Valley, where Salazar’s family has farmed and ranched since before Colorado was a state. Tipton has held the Republican-leaning seat easily since he defeated John Salazar in 2010 – former state Sen. Gail Schwartz, the Democratic nominee, lost by 14 points in the last election – but national Democrats have targeted it this year, and progressive groups say they plan to spend heavily to campaign against the incumbent.