UPDATE: Less than one-third of Missouri voters likely to go to polls Tuesday

 JEFFERSON CITY — The secretary of state's office estimates that less than one-third of Missouri's registered voters will go to the polls during Tuesday's primary elections.

If the estimate holds, about 1.2 million of the 4 million registered to vote in Missouri will cast ballots. The estimate is based on data calculated by local election officials.

At least half of the registered voters are expected to show up in just 17 of the state's 114 counties. Knox County in northeast Missouri has the highest projected turnout with 75 percent of its 2,895 registered voters expected to go to the polls.

Butler County in southeast Missouri is expected to have the lowest turnout with 15 percent of its 31,984 voters expected to cast ballots.

Thirty percent of Boone County's registered voters are projected to participate in the primary. That would be about 32,500 people out of the 108,651 on the rolls.

The polls are open from 6 a.m. to 7 p.m. on Tuesday.