Colorado Republican Party Chairman Ryan Call told CNN he anticipates 80,000 to 100,000 Republicans will head to their caucus sites.
"We are going to have high, record turnout," he said.
The rules for participating in the caucuses are a bit tighter in Colorado, which some observers say could hamper free-wheeling Ron Paul, the U.S. representative from Texas who usually draws independents and young voters to the party. Colorado's caucuses are open only to registered Republican voters -- and only those who registered in their local precinct before Dec. 7.
Paul, conceding he'd lose in Florida, spent most of his time stumping in Colorado and other caucus states.
Paul's campaigning in states that award delegates proportionately is a way to keep him in the hunt.
"We're in third place when it comes to delegates and that's what really counts and we're only getting started," Paul told Politico. "We will be spending time in the caucus states."
It takes 1,144 delegates to win the GOP's national presidential nomination.
The local precinct meetings are a straw poll, the Pueblo Chieftain reported, meaning those who attend their neighborhood meetings will be asked to vote for their favorite candidate but the results won't bind any of Colorado's 36 Republican delegates to support a particular candidate at state or national conventions.
"This is grassroots voting, you get to decide who amongst your neighbors gets to decide who represents you in office," Douglas County Republican Party Chairman Mark Baisley told Castle Rock News. "This is what I love about the whole caucus and assembly process. It's very open. It's very inviting. We get to decide who will represent us by contributing to the platform. It's the answer to that question of 'Who are those guys that keep deciding for me?'"
Front-runner Mitt Romney, who scored a big win in the winner-take-all Florida primary (garnering all of the state's 50 delegates), sailed to victory in Colorado in 2008 over eventual GOP presidential nominee John McCain. (Former House Speaker Newt Gingrich's campaign said last week it was challenging Florida's winner-take-all operation, saying states that conducted primaries ahead of a specific date were to distribute delegates proportionately.)
Robert C. O'Brien, a partner in a national law firm in Los Angeles and a former U.S. representative to the United Nations who advises Romney on foreign policy, said the primary/caucus schedule isn't doing Gingrich any favors. In an online commentary posted on Fox News' Web site, O'Brien noted Gingrich will be out of his wheelhouse for about a month.
Also absent are debates, with the airwaves silent until Feb. 22, just before the Arizona and Michigan primaries at the end of the month.
Despite Romney's history, Colorado could be a bright spot for Gingrich, who held a lead in a month-old poll. Nationally, RealClearPolitics.com indicated Gingrich had a 2.5-percentage point edge over Romney as of Wednesday.
Gallup, however, showed Romney ahead of Gingrich nationally, 31 percent to 26 percent.
But, Colorado also is one of three states the campaign of former U.S. Sen. Rick Santorum is targeting in February because of its evangelicals demographic, CNN said. Focus On The Family founder James Dobson is from evangelical stronghold Colorado Springs and he is firmly in Santorum's camp.