U.S. Sen. Tom Carper of Delaware will campaign for Democratic presidential candidate Joe Biden in Denver on Friday as ballots land in Colorado voters’ mailboxes and the state’s “Super Tuesday” primary moves into the national spotlight.

Carper, the lead Democrat on the Senate Committee on Environment and Public Works and a former governor of Delaware, is scheduled to launch a phone bank focusing on Biden’s stance on public lands in North Denver on Friday morning. He’s also set to take part in a discussion about climate change with community leaders and policy experts, the campaign said.

Biden is one of 14 active Democratic candidates on the March 3 primary ballots that started going in the mail to Colorado voters Monday.

Although he hasn’t held a public appearance in Colorado since launching his presidential campaign last spring, the former vice president raised money in Denver last fall and is scheduled to attend another high-dollar fundraiser on Feb. 17 at the Denver home of former Interior Secretary Ken Salazar.

Presidential primary campaign activity in Colorado is picking up as the nominating contest moves on from last week’s Iowa caucus and Tuesday’s New Hampshire primary.

Former New York Mayor Mike Bloomberg held an event in Denver earlier this month, and former Secretary of Housing and Urban Development Julian Castro campaigned for Massachusetts Sen. Elizabeth Warren in Boulder, Denver and Manitou Springs last weekend. Pete Buttigieg, former mayor of South Bend, Ind., is set to attend a town hall in Aurora on Feb. 22.

On the Republican side, President Donald Trump plans to hold a rally with Colorado Sen. Cory Gardner in Colorado Springs on Feb. 20.