The Gazette's Rachel Riley will be providing live updates from the rallies. Check her Twitter feed (at right for desktop users, below on mobile) for the latest news.
People from both sides of the partisan divide are preparing to rally on Saturday.
In the morning, local activists will gather outside City Hall to call on President Donald Trump to release his tax returns. And in the afternoon, local Republicans will muster in Acacia Park in support of Trump and his policies.
The rally for Trump's tax returns is being coordinated with other demonstrations in Denver and across the country on what is typically the deadline for filing income tax returns, although this year's due date has been moved to Tuesday.
As of Thursday afternoon, more than 100 people had RSVPed to the Colorado Springs rally on Facebook, and upwards of 6,600 had said they were "going" to the march in Denver.
Over the last 40 years, presidents - with the exception of Gerald Ford - have released some of their tax returns. Trump has said he will not release his tax returns because he's being audited by the IRS. His critics say the refusal raises questions about potential conflicts of interest.
"It puts a cloud of suspicion over this president that he won't release his tax return," said Ryan Barry, board president of Unite Colorado Springs, which is organizing Saturday's rally. "We're rallying in support of transparency and in pursuit of openness from this administration."
The demonstration is scheduled from 10 a.m. to noon, starting with music and speakers from the county's Democratic Party, the National Association for the Advancement of Colored People and other area organizations.
The pro-Trump rally later in the day is "a celebration of what he's doing and a show of support," said Trevor Dierdorff, El Paso County Republican Party chairman.
"Their whole message is they want to see the president's tax returns. I care far more about his policy than his tax returns," said Dierdorff.
He said he was not aware of the tax returns demonstration when he planned the afternoon rally.
More than 100 Trump supporters attended a similar event held at the state Capitol on March 4. Dierdorff is expecting 700 to 800 people from the Pikes Peak region. Speakers will include U.S. Rep. Doug Lamborn and state Sen. Owen Hill.
Political scientist Tom Cronin, who teaches at Colorado College, said the juxtaposition of the two rallies is "a good sign of a healthy democracy."
Traditionally, supporters do not rally for winning candidates once they have taken office. But the Republican rally could have to do with Trump's historically low approval ratings, he said.
"I think there are some supporters of his who are worried about his legitimacy and his political base," Cronin said.
He expects the displays of activism that began after Trump's election to continue well into his presidency.
The day after Trump's inauguration, an estimated 7,000 people participated in the Women's March in Colorado Springs, which was part of worldwide protests that attracted more than 2 million people. Since then, local activists have rallied against Trump's efforts to dismantle the Affordable Care Act and tighten immigration policies.
"The partisan divide is greater today than it was in the past. We also have a president that dominates the media in a way that's seldom been the case," Cronin said. "Every meeting, every speech gets full-fledged attention."
The rally for Trump's tax returns was originally scheduled to take place in Acacia Park, but was later moved to the steps of City Hall after organizers were told by the city that the El Paso County GOP was using the park that day, Barry said.
Despite the rallies being scheduled an hour apart, Barry does not anticipate any trouble. Volunteer marshals will be on hand that morning to make sure the crowd "keeps it civil," he said.
The Denver Post and The Associated Press contributed to the reporting of this article.