State officials closed the books Friday on a primary election for the record books, certifying results that include Secretary of State Kris Kobach's 343-vote win over Gov. Jeff Colyer in the GOP race for governor.

More Kansans participated in the primary than they have since 2004, with 27.1 percent of registered voters casting a ballot, said Bryan Caskey, the state's elections director.

Caskey also said the primary featured a record number of advance ballots, with 106,267 votes cast before election day — an increase of at least 16,000 over any previous election. That is about 22 percent of the 487,598 votes cast.

He said the primary was the most exhausting one he has endured in the 20 years he has been at the secretary of state's office. He told the state canvassing board he spent the past two weeks proofreading figures reported by counties — a minor revision narrowed the gap between Kobach and Colyer by seven votes — and had no concerns with the election results.

The canvassing board voted unanimously to certify the numbers. Kobach and Colyer were represented by assistant secretary of state Eric Rucker and Jon Hummell, the governor's chief of staff. Attorney General Derek Schmidt is the board's other member.

"It's one for the history books all right," Schmidt said.

The governor's race may be the closest statewide race in Kansas history, Caskey said, but he is still working to verify that. In addition to the tight race between Kobach and Colyer, two Republican primaries for legislative seats were settled by differences of 60 and nine votes.

On Tuesday, the secretary of state's office will send certificates of nomination to candidates. The deadline to file an objection to a candidate's placement on the ballot is Sept. 7.

Ballots will be sent to military and overseas voters Sept. 22. Advance voting starts Oct. 17, the day after the deadline to register.