Voter turnout in Blue Earth and Nicollet counties appears to exceed 75 percent, as election officials said this Election Day was surely the biggest in raw numbers, and not too shabby as a percentage of eligible voters.

It’s difficult to precisely identify voter turnout by county, because counties don’t know how many of their residents are eligible voters. Statewide data are available, though, and showed a turnout of 77.93 percent.

Nationwide turnout was estimated at 64.1 percent.

Election-night claims in local counties of voter turnout exceeding 90 percent used a different calculation method than is typical.

Instead of using the number of eligible voters, counties used the number of registered voters. Using this method, voter turnout in Blue Earth County was more than 100 percent in 2004 because of high same-day registration, said Patty O’Connor, head of elections for the county.

This year, the county had a “turnout” of almost 91 percent, as 35,183 votes were cast and there were 38,855 residents registered on Election Day.

While only about 1,000 more county residents voted in 2008 than in 2004, pre-registration was up more than 8,000, O’Connor said.

It’s more tricky to determine how many people could have voted.

In 2007, there were an estimated 59,802 residents of Blue Earth County, according to census data. It doesn’t show how many were old enough to vote, but data from 2000 said 78.6 percent of the county’s residents were 18 and older.

If that percentage holds, then there were an estimated 47,004 county residents 18 or older in 2007. That would put voter turnout at 74.6 percent.

That guess doesn’t include factors such as felons who haven’t re-earned their right to vote, and it could be low if many of Mankato’s college students were counted as residents but voted elsewhere.

In Nicollet County, that calculation would put turnout at 76.7 percent.

Auditor-treasurer Bridgette Kennedy said she’s never seen turnout this high over her 37 years with Nicollet County.

In Ridgely Township, there were 59 registered voters and 59 votes.

It’s the county’s only mail ballot precinct, meaning ballots were mailed to each registered voter. Fifty-two of those registered voters used those ballots, and seven people registered on Election Day, she said.