Voters from Miami to Durant head to the polls Tuesday to pick candidates for the 2nd district congressional seat.
On the Republican side, Markwayne Mullin faces George Faught and Rob Wallace takes on Wayne Herriman for the Democratic nomination.
District 2 stretches from the Kansas state line on the north to the Texas line on the south and includes the communities of Claremore to Muskogee and Idabel to Commerce.
The 2nd district is the only Oklahoma congressional district currently represented by a Democrat, Dan Boren.
Run-offs in District 2 will decide who will face-off in November.
Meanwhile, Oklahoma election officials are predicting turnout will be relatively low for Tuesday's primary runoffs, the exception will be the 2nd district which could see more voters than normal.
Polls across Oklahoma are open until 7 p.m.
Elsewhere, there are four Oklahoma state Senate and four Oklahoma House runoffs on Tuesday's ballot.
After the polls close, check with NewsOn6.com for all the results.