Vice President Kamala Harris’ campaign boasted of its superior ground game in battleground states over the weekend, with one Democratic campaign official describing the effort as “bananas big.”

The Harris campaign has repeatedly touted its organizing advantage on the ground in the battle with the Republican nominee, former President Donald Trump. Over the weekend that effort went into overdrive with an army of Harris volunteers knocking on doors, making calls and holding events. All told the Harris campaign has 2,505 staff and 358 offices across such battleground states as Pennsylvania, Wisconsin, Georgia and North Carolina.

In a Sunday afternoon conference call with reporters, a senior campaign official said on Saturday alone they clocked 57,000 volunteer shifts and knocked on 18.5 million doors across the battleground states.

“That’s bananas big,” the campaign official said, describing it as an “extraordinary effort” by volunteers.

According to the campaign, the canvassing effort for Mr. Harris just over the past two days included 870,000 door knocks in Pennsylvania; 721,000 phone calls and 256,000 door knocks in Michigan; 940,000 calls and 256,000 door knocks in Wisconsin; 134,000 door knocks in North Carolina; 100,000 door knocks in Georgia, with 76,000 occurring on Saturday; 100,000 door knocks in Nevada; and 115,000 door knocks in Arizona.

“We truly believe and are seeing that the ground game matters and is having a real impact,” the officials said. “We have the momentum.”

The official attributed the get-out-of-the-vote effort to the increase in young voters heading to the ballot box, adding that young voters made up 18% of the votes cast in Nevada on Friday.

With two days to go, the polls say the election is a dead heat. A New York Times/Siena College poll released Friday revealed Ms. Harris and Mr. Trump are tied at 48% nationally among likely voters.

The race also remains close in the battleground states. Real Clear Politics shows Mr. Trump leading across all seven states by less than half of a percentage point with the exception of Georgia where he leads by roughly two points.