3 p.m.: Montana elections officials say more than 87 percent of voters who applied for absentee ballots had returned them in by mid-day Tuesday.
Election offices mailed out more than 351,600 absentee ballots and voters had returned nearly 307,000 returned by noon.
The returned absentee ballots accounted for 45 percent of the state's nearly 688,000 registered voters.
Emily Dean is the spokeswoman for the Secretary of State's office. She says 15,300 people registered to vote between October 12 and Monday, while another 2,253 completed same-day registration in the first four hours the polls were open Tuesday.
2:45 p.m.: A state employee says she voted to re-elect Democratic Gov. Steve Bullock as a check against conservative leaders in Montana.
Stacey Zyliak works for the Department of Commerce's Community Development Division. The 44-year-old Zyliak says she thinks Democratic governors work better in Montana because they provide balance in the Republican-leaning state.
Bullock is in a tight race against Bozeman software entrepreneur Greg Gianforte, who is making his first run for office.
Gianforte is trying to break a trend of Montanans voting for a Democratic governor in the last three elections. Republicans have held majorities in the state House and Senate since the 2010 elections.
1:30 p.m.: The CEO of a nonprofit organization that seeks to promote science and the arts says she voted against U.S. Rep. Ryan Zinke in part because he's raised "phony" concerns about Syrian refugees becoming terrorists.
Terry Zee Lee of Billings let out a whoop as she left a polling station in Montana's largest city after casting her ballot for Democrat Denise Juneau in the House.
Zinke, a former U.S. Navy SEAL, has made more thorough vetting of refugees a centerpiece of his re-election campaign.
Lee says Zinke's trying to get voters stirred up about a non-issue.
Juneau could become the first American Indian woman elected to Congress, but Lee says neither gender nor race factored into her decision. The 68-year-old says Juneau has "proven her chops" during eight years as Montana's public schools chief.
1 p.m.: Retired home builder Ernie Morrison says he's voting for gubernatorial candidate Greg Gianforte in hopes that the Republican will help diversify Montana's economy.
The 68-year-old Morrison spoke as he prepared to cast his ballot Tuesday at the Yellowstone County fairgrounds in Billings.
Morrison says three of his four children had to leave the state to find work because Montana's economy is too heavily dependent on agriculture.
Gianforte is a former high-tech entrepreneur from Bozeman who's argued that the state's economy is starting to slide and needs to be revitalized.
Morrison says incumbent Democrat Steve Bullock has done little to stop young people leaving the state in hopes of finding better jobs.
11 a.m.: Voting got off to a bit of a late start at one Flathead County precinct because the wrong registration book was printed out.
Flathead County election officials said poll workers discovered the mistake soon after the polls opened at 7 a.m. The correct registration book arrived just before 8:30 a.m., allowing about 100 people in line at Precinct 5 to begin voting.
The Flathead Beacon reports some voters who showed up Tuesday morning had to leave for work and planned to try to vote later.
Emily Dean, spokeswoman for the Secretary of State's office, says she had not heard of any other voting delays in the state.
8:45 a.m.: Voting got off to a bit of a late start at one Flathead County precinct because the wrong registration book was printed out.
Emily Dean, spokeswoman for the Secretary of State's office, says poll workers discovered the mistake right away and would have the updated registration book to the Precinct 5 polling place as soon as possible.
Voters sign the registration book before getting their ballots.
Dean said she had not heard of any other voting delays in the state.
9:30 p.m. Thursday: Montana voters head to the polls to choose their next president, governor, U.S. House representative and a range of down-ticket races.
Most polling stations across the state open at 7 a.m. on Tuesday. They close at 8 p.m.
Even before the first poll opens, many Montana voters will have cast their absentee ballots. The Secretary of State's office says more than 279,000 absentee ballots had been received as of Monday morning.
There are more than 684,000 registered voters in the state.
Along with the top-of-the-ticket races, Montana voters will decide on an open seat for the state Supreme Court, four competitive statewide offices, 125 legislative seats and four citizen initiatives.