Primary races also are set in the 1st, 2nd and 4th congressional districts where the incumbents — U.S. Reps. John Sullivan, R-Tulsa; Dan Boren, D-Muskogee; and Tom Cole, R-Moore — all face challenges from within their party. U.S. Rep. Frank Lucas, R-Cheyenne, the state's senior congressman, won't be challenged until November's general election by Democrat Frankie Robbins, whom Lucas defeated with 70 percent of the vote in 2008.
Mostly Republican primary races will be held for several other statewide posts, including lieutenant governor, auditor, attorney general, treasurer, labor commissioner, insurance commissioner and corporation commissioner.
GOP and Democratic primaries will be held for state superintendent, a post incumbent Democrat Sandy Garrett is resigning from after 20 years in office.
Voters also will consider nominees for seats in the Legislature, which Republicans took control of in 2008 for the first time since statehood.
If no candidate secures 50 percent of the vote, a runoff will be held Aug. 24.