Montana state Sen. Matt Rosendale, a Republican, recently filed papers with the Federal Election Commission to start raising money to run for Congress — he’s just not sure which office yet.

Like several other ambitious Republicans in the state, his decision to run for either the House or Senate will depend on whether Rep. Steve Daines, a freshman Republican, enters the race for Montana’s open Senate seat. Even state Rep. Champ Edmunds, who is currently in the Senate race, has said he would switch races if Daines jumps in.

As Rosendale’s campaign treasurer, Bill VanCanagan, wrote in a note filed Aug. 16 to the FEC, “we will not designate which office is being sought until Representative Steve Daines announces whether he’s seeking re-election for the U.S. House of Representatives or running for the U.S. Senate.”

Either would be a statewide race, as Montana has only one representative in the House.

The Sidney Herald reported last month that Rosendale had already been touring the state to gauge his support. According to his bio on the state GOP website, Rosendale is a real estate broker who moved from Maryland in 2002 to a ranch north of Glendive. He served a term in the state House before being elected to the state Senate in 2012.

The seat of retiring Democratic Sen. Max Baucus is a top pickup opportunity for Republicans and could be a major battleground for the second straight cycle if both parties recruit strong candidates.

Although Daines won by 10 points last year, an open-seat House race could be competitive as well. National Democrats have already met with at least one potential candidate so far: Baucus State Director John Lewis.