BILLINGS, Mont. (AP) — Ryan Zinke, a Montana Republican who served as interior secretary during President Donald Trump's first administration, said Monday that he will not seek reelection to a fifth term in the U.S. House, citing health concerns.

The decision gives Democrats an outside chance to pick up a House seat in a state that has veered to the right politically over the past decade.

Zinke, a former Navy SEAL, said in a letter to constituents that he had undergone multiple surgeries in recent years and faces more medical procedures from injuries sustained during his time in the military. He said his condition, which he did not specify, was not life-threatening but required considerable time for recovery.

“My judgement and experience tell me it is better for Montana and America to have full-time representation in Congress than run the risk of uncertain absence and missed votes," he wrote.

After four years in the Montana Legislature, Zinke was elected to the U.S. House in 2014. He was tapped as Trump's interior secretary in 2017 but resigned in 2018 amid numerous ethics investigations. His political career bounced back in 2022 when Zinke narrowly won in a newly created congressional district in western Montana. He won again in 2024 by a comfortable margin.

Several Democrats already had lined hoping up to challenge Zinke in the November election, including former gubernatorial candidate Ryan Busse and union organizer Sam Forstag.

Gov. Greg Gianforte said in a statement that Zinke had been a “champion for Montana,” first as a SEAL and later in politics. Gianforte won a special House election to fill Zinke’s seat after the Republican joined Trump’s Cabinet.

During his time at the Interior Department Zinke worked to advance Trump's “drill, baby, drill” agenda and increase oil and gas extraction from government lands.

He also advocated for conservation and last year led efforts to remove the potential sales of public lands from a Republican budget proposal, opposing some members of his own party.