Oklahoma is one of more than a dozen states participating in Tuesday's primary that will allot a significant number of delegates to Democratic and Republican presidential candidates.
It will be only the eighth time the state has held a presidential primary. Before the state switched to primaries in 1988, it held party caucuses to select candidates.
The Oklahoma State Election Board reports nearly 35,000 Oklahomans participated in early voting last week. In the 2015 presidential primary, fewer than 15,000 voters completed their ballots early.
More than a dozen states and territories will vote on Tuesday's primaries, garnering the day the nickname of "Super Tuesday".
Oklahoma polls open at 7 am and close at 7 pm. Look for complete coverage throughout the evening at News9.com.