As the last day for registering to vote ended Monday, state and local officials said interest in the Nov. 4 general election remained high.

Since January, 217,160 more Coloradans had registered to vote — 112,753 just since the end of July, according to Secretary of State Mike Coffman's office.

And more than a third, or about 1.1 million, registered Colorado voters have requested mail-in ballots so far, said Richard Coolidge, a spokesman for Coffman.

Coolidge said 88 percent of registered voters in Colorado cast ballots in the 2004 presidential election.

In Denver, 61,304 people had registered to vote from January through Sept. 30, said Alton Dillard, a spokesman for the Denver Clerk and Recorder's Office.

Of those, 31,625 were Democrats, 7,009 were Republicans and 21,404 were unaffiliated.

That brings the total of registered voters in Denver as of Sept. 30 to 403,560, versus 304,706 in 2004.

"You see a spike in voter registration anytime you're heading into a presidential election," Dillard said, adding that presidential contests also attract first-time voters who often don't vote in other elections.

Interest in mail-in ballots is also way up. In 2004, Denver voters cast 66,000 mail-in ballots. So far this year, there have been 140,000 requests for mail-in ballots, Dillard said.

Rio Blanco County Clerk Nancy Amick, president of the Colorado County Clerks Association, said requests for mail-in ballots in her county were through the roof.

"We've already surpassed previous elections," Amick said, "and we're still a month out."

Meanwhile, Coolidge said county clerks had canceled the registrations of 58,453 voters since January, about 2 percent of all registered voters. Most of those — 30,569 — were people who had moved to another county or another state.

Another 13,737 were canceled because of duplicate registrations, while 7,902 were deceased and 2,227 were felons. The remainder included a mix of those who had been inactive for two consecutive federal elections and had not responded to mailings, those who were not citizens and those who had withdrawn their names from voter rolls.

Nine people were removed for having been convicted of voter fraud.

Also Monday, a Maryland-based group called FairVote issued a report saying Colorado and nine other battleground states were not well enough prepared for the expected high turnout.

"There is a serious lack of uniformity between counties" in voting technology and procedures, said Adam Fogel, a co-author of the report for the organization.

Fogel said the group, which received responses from officials in 44 counties, also found that many clerks had no written plans for how they would deploy election resources.

The group, though, did not blame local election officials for the lack of uniformity, saying that more state and federal resources are needed.

Fogel also said Colorado's election system is not necessarily worse than those in other states.

"For the most part, every state has some deficiencies in their election administration," he said.

Amick dismissed the report, saying it ignored options such as early voting and mail-in ballots that alleviate Election Day problems.

"I believe county clerks are prepared," she said. "We've known the scope of presidential elections. I think we're preparing accordingly."

Tim Hoover: 303-954-1626 or thoover@denverpost.com