HELENA — In the crowded race to fill Montana's open U.S. House seat, Republicans have a contested primary this June — but, in reality, Bozeman business executive Steve Daines doesn't have much competition.

Daines, 49, has been campaigning for nearly 18 months, has amassed a campaign war chest well past $600,000, and, in the June 5 primary, faces two political unknowns with minimal campaigns.

If Daines wins the primary, he'll face off this fall against the winner of a seven-way Democratic primary and Libertarian David Kaiser of Victor.

The general-election winner will claim Montana's only congressional seat, which is open this year because incumbent U.S. Rep. Denny Rehberg, R-Mont., is challenging U.S. Sen. Jon Tester, D-Mont.

Daines' opponents in the GOP primary for U.S. House are Vincent Melkus, a U.S. Marine Corps veteran and student from Hardin, and Eric Brosten, an author and former engineer from Helena.

Neither man has any political history or experience in Montana, and their entry in the race the past two months came as a surprise.

So it probably comes as no surprise that Daines is running his campaign no differently than when he was the only Republican in the race, traveling the state and talking about how he's the candidate who stands for "more jobs, less government."

"It's an important message, and it's going to be a message about a pro-growth agenda: How do we get the economy back growing again, and job creation growing again?" he said in an interview last week.

Melkus, 27, has said he's running as a strong conservative and "as an average guy who stands for something," spelling out specifically where he would cut the budget.

He said he's been campaigning on the Internet, using social media like Twitter and Facebook and having friends in Montana talk up his candidacy.

Brosten, 57, said he entered the race to publicize his interest in the "Star Wars" missile-defense system  and how it has been misused.

Daines said he's yet to see either of his competitors this year at any party dinners or events, where candidates traditionally gather to woo potential primary voters and win support.

Daines recently left his job as vice president at RightNow Technologies in Bozeman to concentrate on running for the House seat.

He spent 12 years as vice president at the Bozeman-based company, which employs 1,100 people and develops software systems that help companies interact with their customers via the Internet.

Daines, who ran unsuccessfully for lieutenant governor in 2008, first announced in November 2010 that he would challenge Tester in 2012 for the U.S. Senate. But when Rehberg entered the Senate race in February 2011, Daines switched course, dropping his Senate bid and instead declaring that he would run for Rehberg's seat.

Since then, Daines said he has visited every county in Montana and put thousands of miles on his Chevy pickup.

"We'll be staying on the same course that we've had over the last year, spending a lot of time driving around the state, spending time with Montanans over lots of cups of coffee," he said.