Well over a million Coloradans already turned in their ballots in advance of Election Day. That's nearly half of registered voters in the state as of Friday.
It's the final push, and the candidates are vying for those votes that haven't been cast just yet. Over the next couple days, volunteers plan on spending hours of their time convincing voters to turn in their ballots.
The Hillary Clinton and Donald Trump campaigns are spending lots of time and money in Colorado as recent polls show a tight race.
Trump was in Denver Saturday and Al Gore will campaign for Clinton in Boulder and Jefferson County Monday.
If Clinton loses key battlegrounds in the east like Florida, Colorado's nine electoral votes could be important in deciding who wins the White House.
Both sides are using volunteers to canvass neighborhoods and make phone calls to ensure voters turn in their ballots in time.
"We've had more than 10,000 shifts completed in two days. These are people that are absolutely taking stake in this election and are saying, 'This race matters. This matters for today, this matters for tomorrow, this matters for my children and our future,'" Emmy Ruiz, the Colorado state director for Hillary for America.
"We've had thousands of voters conducting tens of thousands of volunteer hours over just the last 96 hours of the election. I think that says a lot to the enthusiasm on our side. We've had thousands of people at all of our rallies and at each of those rallies we get hundreds of more volunteers," said Ali Pardo, the Colorado communications director for Republican National Committee.
It's too late to mail in ballots but voters can take it to a polling center or 24-hour drop off location until 7 p.m. on Tuesday.