By Martin Kidston/MISSOULA CURRENT

Sen. Bernie Sanders and his campaign opened its Montana headquarters in Missoula on Sunday, where volunteers turned out to work the phones and hit the streets knocking on doors.

The campaign is looking to secure as many of Montana's 21 pledged delegates as possible in the state's proportional Democratic primary on June 7.

“Voters get to decide their proportional allocation whether they support Bernie or (Hillary) Clinton,” said Chris Klarich, state coordinator for the Sanders campaign. “We're working with those folks and giving our grassroots supporters advice on how to continue building the movement and win as many delegates as they can so we can carry Bernie to the national convention in Philadelphia.”

As of Monday morning, Clinton had secured 1,716 delegates to Sanders' 1,433. But with eight state's remaining in the party's primary, the Sanders' campaign remains optimistic that it can make up the difference.

The state Democratic Party also has six super delegates up for grabs.

“We're happy with the grassroots progress that's been made in Montana, and we're definitely excited with the chance we have over the next three weeks to continue building that support,” said Klarich. “We've just seen so much enthusiasm for the campaign.”

While Clinton opened a campaign office in Helena last week, the focus on Montana in the presidential race will likely look to Billings over the next few days. Former President Bill Clinton will stump for Hillary in Billings this Thursday. GOP front-runner Donald Trump is also expected to stop in Billings next week.

Neither campaign has announced any other stops in Montana. Sanders made two stops in Montana last week, including one in Missoula, which drew an estimated 9,000 people. The Sanders' campaign looks to capitalize off the enthusiasm.

“It's clearly the volunteer army that has helped move (Sanders) to the winning category in state after state as we're starting to roll forward,” said Sanders' volunteer Rebecca Holman of Missoula. “When we don't have a lot of money, time is the only other thing we can really give, and time is precious. These last three weeks going up to our primary, that's really all we can do is invest the time.”

Over the past three months, Holman has run a phone bank every Monday at the Union Club. She was also one of several Missoulians to address the rally last Wednesday before Sanders took the stage.

At the new Sanders' headquarters, she's teaching volunteers how to reach out to voters.

“Once they learn how to do the phone banking, they can go home and do the calling on their own,” said Holman. “Missoula has always been a very good grassroots city. For Montana, the base of (Sanders') people are certainly right here in this city, in the heart and soul of western Montana.”

Sanders' volunteer Laura Allred graduated from the University of Montana on Saturday and turned her focus to the Sanders' campaign on Sunday. She said many voters remain undecided.

“There's a lot of support, but there's a lot of undecided people,” said Allred. “It's more undecided than the other extreme.”

Sanders' Montana headquarters office is located at 1806 South Avenue West in Missoula.