March 2, 1:29 a.m.: With 98 percent of precincts reporting, Bernie Sanders had 58.9 percent of the vote over Hillary Clinton’s 40.3 percent. Colorado Democratic Party chairman Rick Palacio said that the turnout for Democrats surpassed that of the 2008 caucuses. Tuesday night, at least 121,232 people voted.

March 1, 9:30 p.m.: Bernie Sanders was headed for a victory over Hillary Clinton in the Colorado caucuses Tuesday, the Associated Press projected at 9:13 p.m.

The Vermont senator was leading the former secretary of state nearly 58 percent to 41 percent, with 67 percent of precincts reporting.

8:15 p.m.: Presidential straw poll results have begun to trickle in from around Colorado in the Democratic caucuses, with urban sites starting to join rural areas in reporting them.

At 8:10 p.m., the first 523 votes were favoring Bernie Sanders over Hillary Clinton, but their vote totals were expected to grow rapidly, with none in yet from Denver.

A Colorado Democratic Party spokesman said protocol is for site leaders to phone in results to a state hotline as soon as presidential straw polls are complete rather than waiting for the end of the caucuses.

PREFERENCE POLLS: Complete Democratic caucus results Mobile users: See results here

Amid larger-than-expected crowds, some caucus locations were forced to improvise Tuesday night. In Fort Collins, one Twitter user posted a photo of people caucusing outside after the fire marshal cleared the overcrowded building.

At North High School in Denver, just-completed votes in three precincts all went Sanders’ way, according to a Denver Post reporter. The vote totals favored Sanders over Clinton 65-60 in one, 54-34 (with one undecided) in the another and 75-34 (with seven undecided) in a third precinct.

One thing to keep in mind: Tuesday’s results will provide only a projection of the eventual winner of Colorado’s 66 delegates to the Democratic National Convention, which will be selected at later meetings up through the party’s April 15 state convention. The state has another 12 superdelegates who decide their support independently.

Also, there is the potential for Clinton to lag Sanders in preference poll votes Tuesday and yet be apportioned more delegates. That is because of congressional district-based math that determines 43 of the delegates, as The Denver Post’s John Frank explains here.

7:45 p.m.: Democratic caucuses got underway Tuesday night — some a little late, as lines still snaked around sites at 7 p.m. — as Colorado partisans prepared to choose between Bernie Sanders and Hillary Clinton.

At East High School, a mega-site hosting 18 precincts, Democrats were still arriving by the dozens, with little hope the caucus would start on time. The party said this week that voters in line at 7 p.m., would be able to participate.

Reports of similar thronging crowds came in from North High School, Skinner Middle School, the Byers Middle School building and Northfield High School in Denver; Arapahoe High School in Centennial; and Mountain View Elementary in Longmont.

“I don’t think people will be able to get into the gymnasium in the first half (of the caucus),” volunteer Carol Heepke said. “I made a lot of phone calls myself to let people know, it’s going to be crowded (and) you should get here early.”

At 7:25 p.m., Mountain View still had hundreds of people lined up outside, but the line was moving amid grumbles from those waiting as turnout appeared to wildly outstrip expectations. Someone passed cupcakes down the line, shouting: “Definitely not gluten-free!”

There were few reports of crowding at smaller sites across the metro area.

At Denver’s East High, candidates such as state House candidate Leslie Herod greeted voters on the sidewalk near the school bicycle racks.

“Leslie and Hillary!” one enthusiastic caucus-goer called out to her from down the street.

Inside East, the crowd calmed with the recitation of the Pledge of Allegiance. Candidates for local offices were limited to a 1-minute campaign pitch — a restriction that raised a cheer from the thousands of caucus-goers. Speeches by the presidential candidates’ surrogates got underway at 7:30 p.m.

At North High, surrogates of candidates were speaking to a large crowd about 7:30 p.m. in the auditorium.

Others were still waiting in the school’s lobby to get in, but there no longer was a line outside.

7 p.m.: Before Colorado’s Democratic caucuses were set to begin across the state, partisans for U.S. Sen. Bernie Sanders of Vermont and former Secretary of State Hillary Clinton lined up outside several caucus spots in Denver.

At East High School, home to 18 precincts near City Park, it was thousands long, stretching 100 yards outside and then at least another 100 yards inside the cavernous school.

“It’s our first chance to vote for Hillary,” said Ann Miller, 66, a staunch backer who was near the front of the line. “We got here at 5:30 p.m. We weren’t going to miss it.”

Eighteen precincts and an estimated 6,000 Democrats were expected by organizers, who herded caucus-goers from the school lunchroom back outside.

PREFERENCE POLLS: Complete Democratic caucus results Mobile users: See results here

But not unexpectedly for Denver, Sanders supporters — many of them young — looked to be holding their ground, showing up strong.

“I’ll stand in the rain if I have to for Bernie Sanders,” said Adam Davis, 21.

That also appeared to be the case at another large caucus site, North High School in northwest Denver. It will have 10 precinct caucuses.

“They’re really turning out,” attendee Jeff Gallinger said about younger voters.

David Cleland was one of the first people at North. He had attended his first caucus eight years ago, and this time he said he planned to vote for Sanders.

“He is saying a lot of the right things to make changes in health care and the education system (that) I’m not hearing Hillary saying,” Cleland said.

Devon Braunstein wasn’t even sure she could get into the caucus. The 24-year-old is from New York and was in town for business. But she came anyway “to experience democracy at work.”

Under party rules, though, she’ll be relegated to observer.

She said for young voters like herself, climate change was a big issue in this election.

“I think it is really important to my generation,” Braunstein said. As of now, she was still undecided between the Democratic candidates. “I think Super Tuesday will determine a lot.”

Earlier today: As Colorado Democrats head to caucus Tuesday night, Bernie Sanders is hoping his anti-establishment message will help him win the state eight years after it went big for Barack Obama.

The Vermont U.S. senator’s opponent, former Secretary of State Hillary Clinton — who lost the caucus vote to rival Obama 2-to-1 in 2008 amid huge turnout — has fought hard, while her campaign has acknowledged Colorado may be an uphill battle. As of a week ago, Sanders had spent more than twice as much as Clinton on TV ads in Colorado leading up to the caucuses.

Heading into Super Tuesday, this dynamic — Sanders as the favorite — is the opposite of what’s expected in a swath of other Democratic presidential nominating contests also being held. Clinton was heavily favored in many of the 10 other states and American Samoa that are having contests, mostly primaries, including several southern states with large African-American voter bases that Sanders has struggled to attract. Early in the evening, results were bearing that out.

That means Colorado may attract some attention as one of a handful of potential firewalls for Sanders.

“This is a state that Sanders almost certainly must win if he is to have any shot at the nomination,” the website FiveThirtyEight says in its Super Tuesday guide.

Still, Colorado has 66 Democratic delegates that will be chosen in a long process that begins at the precinct caucuses — a mere fraction of the 865 delegates at stake Tuesday. That means larger states’ contests likely will overshadow Colorado’s caucuses, which no polling organizations have tried to predict recently because of the state’s lack of a definitive primary.

“The real story Tuesday, as far as I’m concerned, is just that Colorado continues to be a relative non-player,” said Eric Sondermann, a Denver political analyst. “It holds onto this archaic caucus system. We’re one of the ultimate swing states (in November), and yet we’re one of the least important states in the nominating process.”

He added: “In terms of national media coverage, Colorado’s likely to be an afterthought.”

And simply winning the caucuses’ straw poll may prove only symbolic. The real prize, the state party’s delegates to the national convention, can quickly get complicated.

There is the potential for Clinton to lag Sanders in preference poll votes Tuesday and yet be apportioned more delegates. That is because of congressional district-based math that determines 43 of the delegates, as The Denver Post’s John Frank explains here.

The upshot: Tuesday’s results will provide only a projection of the eventual winner of the 66 delegates that will be selected at later meetings up through the party’s April 15 state convention. The state also has 12 superdelegates — not at stake Tuesday — who mostly back Clinton now but can declare or change their allegiances at any time.

At 7 p.m. Tuesday, registered Democrats will file into 3,010 precinct caucuses at more than 400 locations around the state, most at schools, churches and community centers. To participate, voters had to be registered and affiliated as a Democrat by Jan. 4 and must have lived in their precinct for at least 30 days.

They will face several items of party business, including choosing precinct leaders for two-year terms and electing delegates and alternates who will attend county assemblies and possibly the state convention. They also will vote on issue resolutions for the state party platform.

But one of the first orders of business will be the presidential preference poll, which the state party says should occur before 8 p.m. (Colorado Republicans are not having a straw poll at their caucuses Tuesday.)

A representative of each candidate will get an opportunity to make a brief pitch to the precinct meeting. Any tie vote will be decided by coin flip, a drawing of straws or another method of chance.

Officials will report results to the Colorado Democratic Party using a hotline. Into the evening, the party will report the numbers of caucus attendees who supported each candidate.

“I’ll be looking for two things,” Sondermann said. “One is the level of turnout (and) if it comes close to matching the Obama phenomenon of eight years ago,” when about 120,000 Democrats caucused.

“And secondly, I’m assuming that Clinton is going to have a good night around the country. If Sanders is going to stay in the game, he needs to point to three, four or five states. And it’s hard to imagine he’s going to be able to (do that) if Colorado is not one of them.”

Staff writer Jenn Fields contributed to this story.

Jon Murray: 303-954-1405, jmurray@denverpost.com or @JonMurray